20090930

Astronomy current events question: lava planet CoRoT-7/TYC 4799-1733-1

Astronomy 210L, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Kelly Beatty, "CoRoT-7b, The Lava Planet," September 16, 2009
http://www.skyandtelescope.com/news/home/59480512.html
How did the French CoRoT satellite discover the first rocky exoplanet CoRoT-7/TYC 4799-1733-1? Circle your answer below.
(A) Traces of organic compounds associated with life on Earth.
(B) Presence of high plumes of volcanic ash.
(C) Measurements of its mass and size, as it orbits around and passes in front of its star.
(D) Its rotation axis is tilted over on its side.
(E) Infrared light emitted from fresh lava flows on its surface.

Correct answer: (C).

Student responses
Sections 70178, 70186, 70200
(A) : 0 students
(B) : 2 students
(C) : 25 students
(D) : 1 student
(E) : 3 students

20090929

Astronomy current events question: Haumea's red spot

Astronomy 210L, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Bill Andrews, "Haumea’s Newly Discovered Spot," September 16, 2009
http://cs.astronomy.com/asycs/blogs/astronomy/2009/09/16/haumea-s-newly-discovered-spot.aspx
How did an astronomer at the Queens University of Belfast discover a red spot on the dwarf planet Haumea in the Kuiper Belt? Circle your answer below.
(A) Observations of giant storm patterns in its atmosphere.
(B) Data from Voyagers 1 and 2 as they passed through the Kuiper Belt.
(C) Investigating changes in brightness as it rotated.
(D) Recording a giant impact between Kuiper Belt objects.
(E) Changing colors as it passed in front of a distant star.

Correct answer: (C).

Student responses
Sections 70178, 70186, 70200
(A) : 4 students
(B) : 9 students
(C) : 14 students
(D) : 2 students
(E) : 3 students

20090928

Online reading assignment question: smallest star?

Astronomy 210, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

(The following question was asked subsequent to the lecture on Wien's law and the Stefan-Boltzmann law.)

Which star is the smallest in size? (Graded for completion.)
(A) Supergiant.
(B) Giant.
(C) The sun.
(D) White dwarf.
(E) Red dwarf.
(F) (I'm lost, and don't know how to answer this.)

Student responses (pre-instruction)
Sections 70158, 70160
(A) : 0 students
(B) : 0 students
(C) : 1 student
(D) : 29 students
(E) : 36 student
(F) : 6 students

Correct answer: (D)

According to Wien's law, a white dwarf is hotter than a red dwarf. The Stefan-Boltzmann law (luminosity is proportional to size and temperature^4) says that a white dwarf must be much smaller than a red dwarf of the same luminosity, as seen by comparison from a Hertzsprung-Russell diagram.

(Students were then prompted to fill in a text box online to justify their answer.)

Briefly explain your answer, about your choice for smallest star. (Graded for completion.)

The following are all of the student responses to this question, verbatim and unedited.
"I didn't pick one out for the reason that i'm not too sure and I don't have my text book with me to look it up!"

"because it is low in luminosity"

"A red dwarf is a star that is almost burned out."

"They have lower mass than a white dwarf, and they are cooler than a white dwarf."

"i think the sun because it depends on many things anfd it changes alot"

"it was a guess"

"We know they are so small because they have such low luminosities and therefore must have very low surface area."

"i guessed"

"im thinking the white dwarf is a star that had its matter compacted down on itself. Energy is concentrated to a tight compact ball"

"there was a red star found about the same size as jupiter"

"...why else would they call it a dwarf?"

"I am not really sure why."

"it was hopefully a lucky guess"

"a white star is smaller because it is in the last stage of the star life cycle, it has used up all of its nuclear energy...."

"I would think the word dwarf indicates a smaller side"

"The red dwarf is not only small but are also cool. The text book said so."

"I've heard someone say something along the lines of a white dwarf being small..."

"the white dwarfs are the smallest because with time they age and cool down and thats wat makes them get small."

"Red dwarfs are fragments of stars, not entire stars"

"as a sun cools down it expands, and of these options the hottest star is the white dwarf (the sun is a yellow dwarf and supergiants are the largest stars i believe so that is not an option either)."

"because it is...."

"Well giants are huge so there not small. A dwarf is a small person so it was between white and red and i've never seen a small red person."

"Because according to the H-R diagram, white dwarfs are at the bottom"

"I don't know which one is the smallesy in size; I would assume the white dwarf."

"The white dwarves have little surface area and low luminosity."

"Red dwarfs are the smallest"

"Astronomers can calculate the diameter of a star by finding its angular size and its distance from earth."

"i really dont know the answer to the question because i dont know about the sizes of the stars."

"the red dwarf is the smallest star because it is very low in luminosity."

"Dwarfs are the smallest stars."

"Well, the sun is very visible and is massive and the other stars seem to be visible as well."

"because it cannot be a giant so it must be a dwarf. The white is the smallest."

"i don't remember"

"Red dwarfs are as big as half the sun or even smaller."

"Wikipedia claimed it to be so"

"thats just the name of the star"

"The red dwarf is smaller than the white dwarf"

"The red dwarf is the coolest and faintest of the dwarf stars making it appear the smallest."

"i know a dwarf star is small, but i guessed on the color"

"the white dwarf is the smallest"

"Because they have about a .01 R."

"It is basically the last stage of a stars life after it expands to a red dwarf it, not always, becomes a white dwarf. It is smaller but just as dense."

"I am guessing, based on "dwarf"'s indication that it is a smaller star, and that a red star is less hot than a white star."

"book says white is the smallest"

"I think the white dwarf is the smallest."

"The Guiness Book of World Records lists a white dwarf named L362-81 as the smallest star in size; its diameter is estimated to be only about 3500 miles."

"'The Guiness Book of World Records lists a white dwarf named L362-81 as the smallest star in size; its diameter is estimated to be only about 3500 miles, or about the same size as the planet Mercury.' -Or so says my google search engine..."

"Sounds small"

"I just guessed"

"Gary Coleman... Pretty obvious reasons."

"becuase it has the word dwarf in it..."

"It's super small."

"I chose the Red dwarf because i looked it up online."

"A white dwarf is concentrated and new. A red dwarf is a small less concentrated star that has grown a small amount. The White dwarf would be smaller than the red dwarf."

"no idea. it sounded intuitive."

"Whites are usually smaller the reds"

"Because it doesn't generate as much nuclear fusion?"

"because thats what color my lawn gnome is"

"The book lists red and white dwarfs as the smallest, and I'd say it's about 50/50 that I'm right."

"honestly, I guessed.."

"white dwarf are the smallest in size because it ends up losing material when it is in their burning stage"

"i guessed really have no idea"

"i chose the white dwarf because it is a dead star"

"i chose white dwarf because it is the correct answer and should be picked. to pick any other answer would mean i would get the problem wrong and the objective is to get it right.....therefore, i chose white dwarf"

"Dwarfs are tiny people, so perhaps dwarf stars are the littlest stars, and red is cooler than white."

"White Dwarf star's are roughly an average size of the earth, which is not large for a star."

"It says that white dwarfs are the smallest"

"has the smallest diamete"

"becasue thats what google told me"

"A white dwarf is hotter which means its more dense."

"I'm still lost, and I still don't know how to answer that."

"less nuclear reactions"

20090927

Central Coast Astronomical Society monthly meeting: NASA Kepler Misssion

090926-1110782
http://www.flickr.com/photos/waiferx/3964831259/
Originally uploaded by Waifer X

Dr. Laurance Doyle, SETI principal investigator and NASA Kepler Space Telescope mission science team member, giving a presentation on the "NASA Kepler Mission: Detection of (Tatooine-Like) Habitable Planets Around Double Stars" at California Polytechnic University, San Luis Obispo, CA, September 26, 2009, hosted by the Central Coast Astronomical Society. Photo by Cuesta College Physical Sciences Division instructor Dr. Patrick M. Len.

Cuesta College North County campus star party

090910-1110632
http://www.flickr.com/photos/waiferx/3952292654/
Originally uploaded by Waifer X

Cuesta College Astronomy 210L students and guests during a North County campus star party. Photo by Cuesta College Physical Sciences Division instructor Dr. Patrick M. Len.

Sights seen:
Jupiter
Epsilon Lyrae (The "Double-Double")
Alberio (Beta Cygni)
Vega

20090926

Education research: preliminary feedback on flashcards and online reading assignments (Cuesta College, Astronomy 210, Fall Semester 2009)

Cuesta College students taking Astronomy 210 (introductory astronomy) at Cuesta College, San Luis Obispo, CA use flashcards to engage in peer-interaction ("think-(pair)-share") discussion questions during lecture, and complete weekly online reading assignments (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments.

Through the fifth week of instruction, students were given the opportunity to evaluate the instructional components of the course, and the use of flashcards and online reading assignments in an online "Learning Resource Survey" hosted by SurveyMonkey.com. Questions from section II are adapted from the Student Assessment of Learning Gains (SALG) survey (developed by Elaine Seymour, Wisconsin Center for Education Research, University of Wisconsin-Madison), and questions from section III (III.1, III.3, III.5, and III.7) were adapted from a "Clicker Attitude Survey" (N. W. Reay, Lei Bao, and Pengfei Li, Physics Education Research Group, Ohio State University).

These are the complete survey results. Analysis will be forthcoming after more data has been compiled from future semesters. Values for the mean and standard deviations are given next to the modal response category for each question. Note that the order of questions within sections II and III were randomly scrambled for each student.
Learning Resource Survey
Cuesta College
Astronomy 210 Fall Semester 2009 sections 70158, 70160
(N = 59)

I. In order to receive credit for completing this survey,
first enter your first and last name below:
____


II. How much did each of the following aspects of the class help
your learning?

II.1 Lecture by instructor.
1. Strongly disagree 1 : *
2. Disagree 6 : ******
3. Neutral 11 : ***********
4. Agree 29 : ***************************** [3.9 +/- 0.9]
5. Strongly agree 12 :************

II.2 Working in groups on in-class activities.
1. Strongly disagree 1 : *
2. Disagree 1 : *
3. Neutral 10 : **********
4. Agree 25 : ************************* [4.1 +/- 0.9]
5. Strongly agree 22 : **********************

II.3 Using flashcards to participate in class.
1. Strongly disagree 1 : *
2. Disagree 4 : ****
3. Neutral 7 : *******
4. Agree 31 : ******************************* [4.0 +/- 0.9]
5. Strongly agree 16 : ****************

II.4 Reading the textbook.
1. Strongly disagree 1 : *
2. Disagree 4 : ****
3. Neutral 14 : **************
4. Agree 33 : ********************************* [3.7 +/- 0.8]
5. Strongly agree 6 : ******

II.5 Demonstrations/videos in class.
1. Strongly disagree 2 : **
2. Disagree 2 : **
3. Neutral 7 : *******
4. Agree 24 : ************************ [4.1 +/- 1.0]
5. Strongly agree 23 : ***********************

II.6 Interacting with other students during class.
1. Strongly disagree 0 :
2. Disagree 2 : **
3. Neutral 7 : *******
4. Agree 30 : ****************************** [4.1 +/- 0.8]
5. Strongly agree 19 : *******************

II.7 Interacting with other students outside of class.
1. Strongly disagree 4 : ****
2. Disagree 11 : ***********
3. Neutral 23 : *********************** [3.1 +/- 1.1]
4. Agree 19 : *******************
5. Strongly agree 2 : **

II.8 Online reading assignments.
1. Strongly disagree 2 : **
2. Disagree 11 : ***********
3. Neutral 21 : ********************* [3.3 +/- 1.0]
4. Agree 20 : ********************
5. Strongly agree 5 : *****

III. Answer the following statements which may or may not describe
your beliefs about the use of flashcards in this class.

III.1 I like using flashcards.
1. Strongly disagree 0 : 0
2. Disagree 3 : ***
3. Neutral 17 : *****************
4. Agree 27 : *************************** [3.8 +/- 0.8]
5. Strongly agree 12 : ************

III.2 Flashcards helped me understand lectures better.
1. Strongly disagree 0 :
2. Disagree 8 : ********
3. Neutral 11 : ***********
4. Agree 28 : **************************** [3.7 +/- 0.9]
5. Strongly agree 12 : ************

III.3 I would recommend using flashcards in future semesters of this class.
1. Strongly disagree 0 :
2. Disagree 4 : ****
3. Neutral 13 : *************
4. Agree 24 : ************************ [3.9 +/- 0.9]
5. Strongly agree 18 : ******************

III.4 I will avoid other classes using flashcards in future semesters.
1. Strongly disagree 20 : ********************
2. Disagree 27 : *************************** [1.9 +/- 2.7]
3. Neutral 9 : *********
4. Agree 2 :
5. Strongly agree 1 :

III.5 Flashcards were a positive experience.
1. Strongly disagree 0 :
2. Disagree 3 : ***
3. Neutral 9 : *********
4. Agree 34 : ********************************** [4.0 +/- 0.8]
5. Strongly agree 13 : *************

III.6 Too much time in class was spent using flashcards.
1. Strongly disagree 11 : ***********
2. Disagree 32 : ******************************** [2.2 +/- 1.6]
3. Neutral 10 : **********
4. Agree 6 : ******
5. Strongly agree 0 :

III.7 Too many flashcard questions were asked.
1. Strongly disagree 13 : *************
2. Disagree 30 : ****************************** [2.1 +/- 1.8]
3. Neutral 11 : ***********
4. Agree 5 : *****
5. Strongly agree 0 :

III.8 Using flashcards was difficult.
1. Strongly disagree 27 : *************************** [1.8 +/- 3.5]
2. Disagree 21 : *********************
3. Neutral 9 : *********
4. Agree 2 : **
5. Strongly agree 0 :

IV. (Optional.) Please type in any comments you may have regarding
the use of flashcards in Astronomy 210.
The following are all of the student responses to this question, verbatim and unedited.
"Its something different because I have never done that in any of my college courses, but its cool because changes like that could be good and useful! I really don't mind them at all, its actually kind of fun to see what people answers are and why!"

"have they every proved to be effective?"

"Flashcards are a great way to get students to feel confident about their understanding of concepts. Also, when a student is wrong or thought they knew a concept and they didn't, they can converse with the people around them to come up with the right answer."

"You never fully explain the answer, therfore I'm always a little lost and confused and so are the people next to me."

"i feel nothing gets explained well enough and then we jump to flashcards and the majority of the class is confused and nothing sinks in."

"Its a good way to review a little bit every day on the material"

"They help!"

"Good Idea, keeps class on their toes."

"I think the use of flashcards is a good thing. We are able to see how well we know the material and hopefully learn it if we don't. The one think I don't like is when we get the question wrong the 2nd time and the answer isn't given. It only happened a few times so its not that big of a deal."

"you don't always give the right answer, so sometimes i get confused on what the answer really is and if i got it or not."

"The flash cards really helped because if the instructor was not satisfied with the amount of correct answers he would make us discuss and explain to each other why we thought the answer we chose was the right one to another person. By doing this we start a small debate group until we come up with a conclusion."

"There is often no way to tell what is right before we hold up the cards"

"they are very helpful when explained."

"I like the use of flashcards because you can see where you are compared to everyone else in the class and any misunderstandings on the questions are cleared up when using them."

"i really enjoy using flashcards in class. it gives me an oppertunity to know what is on the test, know what to study, and helps me better understand the material we have gone over in a new way so that i am fully confident that i know the material."

"They are alright I think that sometimes the professor should help us answer them when we are lost not just rely on other class mates."

"Its a unique idea that i've never experianced before, thank you so much for introducing it to me."

"Talking about our flashcard answers with other students is helpful."

"Flashcards has helped because after you can discuss with others the right answer"

"Flashcards are a good way to give the instructor feedback as well as a way to discuss with fellow students."

"Flashcards rock"

"I like the flashcard questions, but sometimes I feel like I still don't know the answer after the question has been finished. It would help me if the instructor would spend a minute or two discussing what the correct answer is and why, instead of relying on peer education. More often than not, the people around me either don't know the answer or don't care about the activity and so my learning opportunity is decreased."

"This is a cool learning style in the class"

"When a lot of the class aren't agreeing with each-other then i think you should explain it better until we all get it, or when most of us have the answer still explain why that is the answer.
"hella like them"

"I would like to see flashcard adventures. Take a story and have the classes answers progress that story. (I am stranded in the desert with nothing but my starwheel. I need to get to shelter that I know is supposed to be east. What constellation should I go towards if it is 1 am when I start my perilous trek?) That kind of thing. Put some spice into it!"

"I feel that flashcards help the students understand the concepts."

"Flashcards help in class because if a person doesn't know what the answer is they can at least try to get it and when they get the answer correct or not the correct answer will always be provided by the P-dog"

"Flashcards are awesome. They really helped me understand what was going on."

"they really help prep for quizzes"

"I like them. Thought I think deeper explanations of the questions would be good after the class has answered it"

"I think that when no one knows the answer more help should be given then it currently is."

"they are fun"

"Flashcards are alright, they are a little pointless if you have no idea going into answering the question. But they are kind of fun. I've heard of an electrical flashcard system/quiz system that works pretty well."


V. Answer the following statements which may or may not describe 
your beliefs about the use of the online reading assignments in this class.

V.1 I like working on the online reading assignments.
1. Strongly disagree 0 :
2. Disagree 9 : *********
3. Neutral 15 : ***************
4. Agree 24 : ************************ [3.6 +/- 0.9]
5. Strongly agree 10 : **********

V.2 Online reading assignments helped me understand lectures better.
1. Strongly disagree 1 : *
2. Disagree 13 : *************
3. Neutral 14 : **************
4. Agree 24 : ************************ [3.4 +/- 1.0]
5. Strongly agree 7 : *******

V.3 I would recommend using online reading assignments in future semesters of this class.
1. Strongly disagree 0 :
2. Disagree 8 : ********
3. Neutral 14 : **************
4. Agree 26 : ************************** [3.7 +/- 0.9]
5. Strongly agree 11 : ***********

V.4 I will avoid other classes using online reading assignments in future semesters.
1. Strongly disagree 15 : ***************
2. Disagree 33 : ********************************* [2.0 +/- 2.1]
3. Neutral 8 : ********
4. Agree 2 : **
5. Strongly agree 1 : *

V.5 Online reading assignments were a positive experience.
1. Strongly disagree 0 :
2. Disagree 6 : ******
3. Neutral 20 : ********************
4. Agree 24 : ************************ [3.6 +/- 0.9]
5. Strongly agree 9 : *********

V.6 Too much time outside of class was spent working on online reading assignments.
1. Strongly disagree 13 : *************
2. Disagree 34 : ********************************** [2.1 +/- 1.8]
3. Neutral 8 : ********
4. Agree 4 : ****
5. Strongly agree 0 :

V.7 Too many online reading assignment questions were asked.
1. Strongly disagree 13 : *************
2. Disagree 36 : ************************** [2.0 +/- 1.8]
3. Neutral 7 : *******
4. Agree 3 : ***
5. Strongly agree 0 :

V.8 Completing the online reading assignments was difficult.
1. Strongly disagree 19 : *******************
2. Disagree 29 : ***************************** [2.0 +/- 2.6]
3. Neutral 4 : ****
4. Agree 7 : *******
5. Strongly agree 0 :

VI. (Optional.) Please type in any comments you may have regarding
the online reading assignments in Astronomy 210.
The following are all of the student responses to this question, verbatim and unedited.
"I really enjoy doing them and the surveys too they're easy points. You cant go wrong with taking a few mins to do them and earning the points for it wether your right or wrong ! They do help understand the material better and it motives you to read on it if you're not sure of a question! =)"

"do the assignments prove to be helpful?"

"I just think that more time should be spent going over the actual book itself in class."

"they dont really help me"

"Helpful with regards to tracking how the student feels as the semester progresses."

"I actually enjoy them!"

"The online reading assignments were very helpful because they help understand the reading you do."

"Online reading assignments rarely help me out with the course material."

"theyare helpful and stmuloate ones brain in preparation for future lectures."

"I like the online reading assignments because they're easy :D"

"the online reading assignments are short and very helpful in preparing me what to expcept for our next class."

"I think that the online reading assignment should close before next class not midnight the night before because class is at 11 so students should be able to access it till that point."

"It helps direct me on what i should be getting out of the reading."

"I learn better by reading books and using paper...not the computer."

"The online reading assignments are kinda rough"

"Good length of reading for online assignments"

"Online reading assignments are chilllin"

"The only thing I dislike about the online reading assignments is that they are not discussed much in class. Since students are basically guessing at the answers, they do not get the full benefit of the activity. I think it would be better to assign the questions after the lecture, instead of before, as a review activity. It doesn't make sense to me to have homework on a subject before the subject is covered in lecture."

"good"

"I forgot we had online obligations at the start, so forgot to do the online assignments, which sucked to then lose points for it, but having us do more assignments than is needed will hopefully make up for it in the end."

"i enjoy them."

"they are ok"

"Nothing I can think of."

"They are fine and not a hassle to do"

"The online reading assignments were ok. I like them because it is different than the normal homework. Its good to spice things up."

"sometimes getting the online reading assignments done in time was a difficult thing... especially when my internet likes to go crazy on me!!!!"

"they're legit. kinda silly. easy points so i'm happy"

"I like online activities."

"YAY ASTRONOMY"

"They are okay, again, it helps reading the book before doing them. It's almost to easy to sign in and answer a bunch real quick without much thought.... But this is also nice at the same time..."

20090925

Online reading assignment question: Doppler-shifted car horns

Astronomy 210, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

(The following question was asked subsequent to the lecture on Doppler shifts.)

Suppose you are standing on the sidewalk as a car, with its horn continuously on, comes from behind you, passes by, and continues on ahead of you. How does the pitch of the car horn change as this happens? (Graded for completion.)
(A) Its pitch starts out high, then drops lower.
(B) Its pitch starts out low, then goes higher.
(C) Its pitch is low, goes higher, then drops back down to low.
(D) Its pitch is high, goes lower, then goes up to high.
(E) (I'm lost, and don't know how to answer this.)

Student responses (pre-test, all responses)
Sections 70158, 70160
(A) : 8 students
(B) : 2 students
(C) : 59 students
(D) : 1 student
(E) : 2 students

Correct answer: (A)

Students seemed to conflate pitch (frequency) with loudness (intensity). Because of these responses, students were then shown the following video at the start of class, and told to discuss in a think-pair-share format what happens to pitch rather than loudness before answering again using flashcards.

Dopper Effect
http://video.google.com/videoplay?docid=-7337076920663696115&q=doppler+effect&total=213&start=0&num=10&so=0&type=search&plindex=0
Students demonstrate the change in frequency that occurs as a car blowing its horn moves by an observer (Delsea Regional High School, Franklinville, NJ).

20090924

Online reading assignment question: pre- and post- first quiz opinions

Astronomy 210, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

2009-07 Quiz 01 advice Wordle
http://www.flickr.com/photos/waiferx/3948715709/
Originally uploaded by Waifer X

Wordle.net tag cloud of student advice to future semesters of Astronomy 210 students at Cuesta College, San Luis Obispo, CA.

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

(The following question was asked subsequent to, and then again following the first quiz of the semester.)

How difficult do you think Quiz 1 will be? (How difficult did you think Quiz 1 was?) (Graded for completion.)
(VD) Very difficult.
(D) Difficult.
(N) Neutral.
(E) Easy.
(VE) Very easy.

Student responses (pre-test, all responses)
Sections 70158, 70160
(VD) : 9 students
(D) : 36 students
(N) : 20 students
(E) : 5 students
(VE) : 0 students

Student responses (post-test, all responses)
Sections 70158, 70160
(VD) : 2 students
(D) : 27 students
(N) : 34 students
(E) : 6 students
(VE) : 1 student

Of the 70 students who had answered the pre-test question, and the 70 students who had answered the post-test question, 55 students had answered both the pre-test and post-test questions (while 15 students answered only the pre-test, and 15 students only answered the post-test question).

Student responses (pre-test responses only, no post-test responses, N = 15)
Sections 70158, 70160
(VD) : 2 students
(D) : 8 students
(N) : 4 students
(E) : 1 student
(VE) : 0 students

Student responses (no pre-test responses, post-test responses only, N = 15)
Sections 70158, 70160
(VD) : 1 student
(D) : 6 students
(N) : 7 students
(E) : 1 student
(VE) : 0 students

Of the 55 students who answered both the pre-test and post-test questions, 24 students had no change in their opinion, while 31 students changed their opinion.

Student responses (pre-test and post-test responders, no change in opinion, N = 24)
Sections 70158, 70160
(VD) : 0 students
(D) : 11 students
(N) : 11 students
(E) : 2 students
(VE) : 0 students

Student responses (pre-test and post-test responders, change in opinion, N = 31)
Sections 70158, 70160
(VD) : pre: 7 students; post: 1 student
(D) : pre: 17 students; post: 10 students
(N) : pre: 5 students; post: 16 students
(E) : pre: 2 students; post: 3 student
(VE) : pre: 0 students; post: 1 student

A Student t-test on all 55 students who answered both the pre-test and post-test questions (24 students with no change in their opinion together with the 31 students that changed their opinion) results in p = 0.0071, and thus there is a statistically significant difference between pre-test and post-test responses.

For the students who took both and responded differently to the pre-test and post-test questions, here were the shifts:

(VD) to (D): 4 students
(VD) to (N): 1 student
(VD) to (E): 1 student
(VD) to (VE): 1 student
(D) to (VD): 1 student
(D) to (N): 14 students
(D) to (E): 2 students
(N) to (D): 5 students
(E) to (D): 1 student
(E) to (N): 1 student

"Negative shifts" in opinion (e.g., towards difficult): 8 students
"Positive shifts" in opinion (e.g., towards east): 23 students
(Compare with the 24 students with no shifts in opinion.)

Thus there was significant shift towards positive opinions regarding the first quiz, after students received had their grades.

Students were given the opportunity to reflect upon their studying and offer advice to future students before taking their first quiz; responses are listed below verbatim, and summarized graphically as a Wordle at the top of this article.

What advice would you give to a student next semester studying for Quiz 1? (Graded for completion.)
"to study notes and study them well to make sure they really do understand it. Even take one or two of the practie quizzes also!"

"read. read. read. ask a lot of questions."

"I would tell them to thoroughly go over the flashcards from all of the classes up until the Quiz. To also know the starwheel."

"Know how to use your starwheel!"

"Even if yhour sick go to class."

"dont get lazy and study"

"Pray to the star gods for righteous mastery of the star chart"

"STUDY STUDY STUDY!!! ASK QUESTIONS IF YOU DON'T UNDERSTAND!!"

"Everything discussed in class was almost exactly like it on the quiz. As long as you understood everything in class, you'll do fine."

"Well, I didn't feel it was very hard, so I guess they should make sure to do the reading and pay attention in class."

"read and pay attention"

"make sure you pay attention to how you use your star wheel"

"I never took the quiz so I wouldn't know what to tell them."

"Make sure you understand moon cycles and you know how to use your star wheel."

"Sleep well the night before."

"to study moon cycles"

"practice"

"Focus on what P. Dog asks you to focus on and really understand how to use your star wheel"

"Take more notes and study more I guess."

"pay attention in class"

"To study the diagrams that are in the text book and pay attention to the in class activity."

"Read the TEXTBOOK!"

"Just try to understand the group things that you do everyday in class. If you understand all that the quiz is easy."

"Read your textbook."

"Take the quizes from the last semesters for extra practice"

"Practice flashcard questions on your starwheel to reinforce the concepts."

"Do all the practice quizzes on the 'goals' section."

"Read chapters one and two and study the slides and flashcard questions on waiferx.com."

"Really study moon phases!!"

"advice i would give a student next semester would be to study the in-class activities and to look at previous quiz questions that p-dog posts on the internet."

"Study Flash Card Questions"

"Definitely figure out the difference between AM and PM."

"I studied alot but the advice I would give is to constantly test yourself on the information you have to know."

"crossing out a wrong answer is a good idea on every question"

"study all of your notes including the hours of the day when the sun is up in different seasons."

"Be prepared for anything!"

"Make sure you understand the in class activities and the star wheel."

"study more than 20 min"

"study"

"learn the moons phases and how to use the starwheel efficiently"

"Practice using your starwheel"

"study"

"pay attention in class"

"dont over study. if you know it, you know it."

"Look back at the old tests and study from those."

"study and make sure you show up"

"use the start wheel and get make sure how to use it correctly. It will help u a lot ."

"read..."

"Do the old quizes."

"pay attention in class."

"Just pay attention to whats goin down in p-dizzles hood, keep it real."

"Be sure to understand your starwheel."

"Study all the concepts covered in the lecture."

"To study the flash card questions that everyone participated in during class time. Also to know forward and backward of how to sufficiently use the star wheel."

"have a break prior to astronomy so you can cram."

"Make sure you have a good grasp of concepts before taking the test."

"Use the quizzes on this website."

"Study, study, study.."

"Study all the questions on the sample quizzes and ask questions on things that one might not understand."

"STUDY"

"Read the chapter but don't over study it. Most the quiz questions are from work done in class."

"study or something"

"Study"

"study more than i did"

"remember the stuff from the first day, and possibly study a little bit"

"learn from your group members, and study not from the book but p dog's lectures."

"Go to office hours if you don't understand somthing"

"ask questions"

"Listen to P-Dogg! He knows his stuff! UHHHHH. And study those practice quizzes and ask questions!
try to remember all the in-class activities that were presented in class."

20090923

Astronomy current events question: refurbished Hubble Space Telescope

Astronomy 210L, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Space Telescope Science Institute press release, "Hubble Opens New Eyes on the Universe," September 9, 2009
http://www.nasa.gov/mission_pages/hubble/science/ero_images.html
What was done to the newly refurbished NASA Hubble Space Telescope in order to obtain new ultraviolet to near-infrared images? Circle your answer below.
(A) A new imaging camera was installed.
(B) Its primary mirror was cleaned.
(C) Nanotechnology filters replaced older laminated plastic filters.
(D) Its orbit was boosted farther out away from Earth.
(E) More liquid helium coolant was added to its reservoir tank.

Correct answer: (A).

Student responses
Sections 70178, 70186, 70200
(A) : 51 students
(B) : 3 students
(C) : 4 students
(D) : 3 students
(E) : 2 students

20090922

Astronomy current events question: white dwarf with companion star

Astronomy 210L, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Astronomy.com editors, "XMM-Newton Telescope Uncovers a Celestial Rosetta Stone," September 3, 2009
http://www.astronomy.com/asy/default.aspx?c=a&id=8600
The European Space Agency XMM-Newton orbiting x-ray telescope has imaged a white dwarf circling a companion star. What is predicted to eventually happen to this white dwarf? Circle your answer below.
(A) Explode in a few million years, bright enough to be seen in daylight.
(B) Collapse into a black hole, swallowing up its companion star.
(C) Feeding on its companion star, becoming large enough to be a main sequence star.
(D) Slowly die off, falling into its companion star.
(E) Drift away after its companion star dies, on a collision course with Regulus.

Correct answer: (A).

Student responses
Sections 70178, 70186, 70200
(A) : 24 students
(B) : 1 student
(C) : 5 students
(D) : 3 students
(E) : 0 students

20090921

Astronomy current events question: LCROSS booster destination

Astronomy 210L, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Astronomy.com editors, "The Lunar Crater Observation and Sensing Satellite Reveals Target Crater for Lunar South Pole Impacts," September 11, 2009
http://www.astronomy.com/asy/default.aspx?c=a&id=8615
The NASA Lunar Crater Observation and Sensing Satellite (LCROSS) has separated from its upper-stage rocket booster. Where is this rocket booster now headed? Circle your answer below.
(A) Back towards Earth, over a remote part of the Pacific Ocean.
(B) In low Earth orbit, to dock with the International Space Station.
(C) To be a target for an U.S. Air Force anti-asteroid missile test.
(D) Impacting the moon to kick up debris that will be analyzed.
(E) Returning to eventually ferry LCROSS-2 to the moon.

Correct answer: (D).

Student responses
Sections 70178, 70186, 70200
(A) : 4 students
(B) : 1 student
(C) : 1 student
(D) : 22 students
(E) : 2 students

20090920

Astronomy quiz question: total lunar eclipses

Astronomy 210 Quiz 2, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Why does a total lunar eclipse not occur every time the moon is full?
(A) The orbit of the moon is not a perfect circle, but is an ellipse.
(B) The moon rotates such that it always keeps the same side facing Earth.
(C) The orbit of the moon around Earth is tilted with respect to the orbit of Earth around the sun.
(D) The direction of Earth's axis precesses over a 23,000 year cycle.

Correct answer: (C)

When the moon is full, it is on the opposite side of Earth from the sun, but due to its tilted orbit may be either above or below Earth's umbral and penumbral shadow zones, such that there is no (total) lunar eclipse.

Response (A) explains why some solar eclipses are annular rather than total. Response (B) explains why the near side of the moon is constant; response (D) is the reason why Polaris will not always be the pole star.

Section 70158
(A) : 9 students
(B) : 3 students
(C) : 36 students
(D) : 1 student
(blank): 1 student

Success level: 74% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.47

20090919

Astronomy quiz question: annular/total solar eclipses

Astronomy 210 Quiz 2, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Why are some solar eclipses annular rather than total?
(A) The orbit of the moon around Earth is tilted with respect to the orbit of Earth around the sun.
(B) The orbit of the moon not a perfect circle, but is an ellipse.
(C) The moon rotates such that it always keeps the same side facing Earth.
(D) The direction of Earth's axis precesses over a 23,000 year cycle.

Correct answer: (B)

During a total solar eclipse, the moon blocks the entire sun, when observed from within the umbral shadow spot on Earth. However, due to the elliptical orbit of the moon, it may be unable to completely block the entire sun as seen from Earth, due to its distance from Earth being too far.

Response (A) explains why a total solar eclipse does not occur every time the moon is new. Response (C) explains why the near side of the moon is constant; response (D) is the reason why Polaris will not always be the pole star.

Section 70160
(A) : 25 students
(B) : 16 students
(C) : 0 students
(D) : 1 student

Success level: 43% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.82

20090917

Astronomy current events question: distant galaxy with black hole

Astronomy 210L, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Astronomy.com editors, "University of Hawaii astronomer finds giant galaxy hosting the most distant supermassive black hole," September 4, 2009
http://www.astronomy.com/asy/default.aspx?c=a&id=8603
How was a University of Hawaii astronomer able to obtain images of a giant galaxy containing the most distant black hole ever found? Circle your answer below.
(A) Computer simulations of a collision between satellite galaxies and the Milky Way.
(B) Faint radio signals received by the Arecibo Observatory in Puerto Rico.
(C) Cave paintings of the same galaxy, much younger, dating back to the Pleistocene era.
(D) Re-examining archived images from the Hubble Space Telescope.
(E) A new red-sensitive camera on the Subaru telescope on Mauna Kea.

Correct answer: (E).

Student responses
Sections 70178, 70186, 70200
(A) : 4 students
(B) : 1 student
(C) : 1 student
(D) : 1 student
(E) : 58 students

20090916

Astronomy current events question: Apollo 12 remnants

Astronomy 210L, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Victoria Jaggard, "NEW MOON PHOTO: Apollo 12 Site Seen With Craft, Prints," September 4, 2009
http://news.nationalgeographic.com/news/2009/09/090904-apollo-12-landing-picture.html
How was NASA recently able to obtain images on the surface of the Moon of the remnants of the Apollo 12 mission? Circle your answer below.
(A) A high-resolution camera aboard the Lunar Reconnaissance Orbiter.
(B) A test run of the newly refurbished Hubble Space Telescope.
(C) Photos provided by the new Russian Lunar Rover.
(D) Previously undeveloped negatives that were lost in the National Library Archives.
(E) The rebooted Apollo 12 lunar lander camera, recharged with solar power.

Correct answer: (E).

Student responses
Sections 70178, 70200
(A) : 28 students
(B) : 5 students
(C) : 2 students
(D) : 0 students
(E) : 6 students

20090915

Astronomy current events question: Milky Way collision

Astronomy 210L, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Astronomy.com editors, "Galactic bombardment unlikely to destroy Milky Way," September 1, 2009
http://www.astronomy.com/asy/default.aspx?c=a&id=8595
According to computer simulations run by astronomers at Ohio State University, what would be the result of a satellite galaxy colliding with our Milky Way? Circle your answer below.
(A) The Milky Way would destabilize, splitting into many smaller galaxies.
(B) More dark matter would be produced, thus protecting the Milky Way.
(C) The satellite galaxy would steal stars and gas from the Milky Way.
(D) The satellite galaxy would fall into the Milky Way's central supermassive black hole.
(E) The outer edge of the Milky Way would flare outwards.

Correct answer: (E).

Student responses
Sections 70178, 70186, 70200
(A) : 4 students
(B) : 7 students
(C) : 6 students
(D) : 8 students
(E) : 40 students

20090914

Astronomy current events question: disappearing sunspots

Astronomy 210L, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Tony Phillips, "Are Sunspots Disappearing?" September 3, 2009
http://science.nasa.gov/headlines/y2009/03sep_sunspots.htm?list212050
What have researchers at the National Solar Observatory theorized about the cause of Sun's disappearing sunspots? Circle your answer below.
(A) Weakening magnetic fields.
(B) Decreasing fusion in the core.
(C) Earth's magnetic poles are about to flip.
(D) Main sequence lifetime ending.
(E) An impending giant solar flare.

Correct answer: (A).

Student responses
Sections 70178, 70200
(A) : 15 students
(B) : 5 students
(C) : 2 students
(D) : 0 students
(E) : 2 students

20090913

Erasing slate: this is sweet

"Hello this is SWEET" by Anonymous
September 1, 2009
Cuesta College, San Luis Obispo, CA

Latest scribbling on the lift-and-erase slate in the hallway, outside the office door.

20090912

Education research: preliminary feedback on flashcards (Cuesta College, Physics 205A, Fall Semester 2009)

Cuesta College students taking Physics 205A (college physics, algebra-based, mandatory adjunct laboratory) at Cuesta College, San Luis Obispo, CA use numerical keypad clickers (Classroom Performance System, einstruction.com) to enter homework and to engage in peer-interaction ("think-(pair)-share") discussion questions during lecture.

However, during the first two to three weeks of instruction, students are first coached through the "think-(pair)-share" process using flashcards instead of clickers. At the end of the third week of the semester, students were given the opportunity to evaluate the instructional components of the course, and the use of flashcards in an online "Learning Resource Survey" hosted by SurveyMonkey.com. Questions from section II are adapted from the Student Assessment of Learning Gains (SALG) survey (developed by Elaine Seymour, Wisconsin Center for Education Research, University of Wisconsin-Madison), and questions from section III (III.1, III.3, III.5, and III.7) were adapted from a "Clicker Attitude Survey" (N. W. Reay, Lei Bao, and Pengfei Li, Physics Education Research Group, Ohio State University).

These are the complete survey results. Analysis will be forthcoming after more data has been compiled from future semesters. Values for the mean and standard deviations are given next to the modal response category for each question. Note that the order of questions within sections II and III were randomly scrambled for each student.
Learning Resource Survey
Cuesta College
Physics 205A Fall Semester 2009 sections 70854, 70855, 72177
(N = 30)

I. In order to receive credit for completing this survey,
first enter your first and last name below:
____


II. How much did each of the following aspects of the class help
your learning?

II.1 Lecture by instructor.
1. Strongly disagree 2 : **
2. Disagree 2 : **
3. Neutral 6 : ******
4. Agree 12 : ************ [3.7 +/- 1.1]
5. Strongly agree 7 : *******

II.2 Doing unassigned textbook problems/clicker questions/practice quizzes.
1. Strongly disagree 0 :
2. Disagree 0 :
3. Neutral 6 : ******
4. Agree 14 : ************** [4.1 +/- 0.7]
5. Strongly agree 9 : *********

II.3 Using flashcards to participate in class.
1. Strongly disagree 2 : **
2. Disagree 2 : **
3. Neutral 4 : ****
4. Agree 16 : **************** [3.7 +/- 1.1]
5. Strongly agree 6 : ******

II.4 Reading the textbook.
1. Strongly disagree 0 :
2. Disagree 1 : *
3. Neutral 10 : **********
4. Agree 13 : ************* [3.8 +/- 0.8]
5. Strongly agree 5 : *****

II.5 Demonstrations/videos in class.
1. Strongly disagree 1 : *
2. Disagree 1 : *
3. Neutral 10 : **********
4. Agree 13 : ************* [3.6 +/- 0.9]
5. Strongly agree 4 : ****

II.6 Interacting with other students during class.
1. Strongly disagree 0 :
2. Disagree 2 : **
3. Neutral 2 : **
4. Agree 15 : *************** [4.2 +/- 0.8]
5. Strongly agree 11 : ***********

II.7 Interacting with other students outside of class.
1. Strongly disagree 0 :
2. Disagree 1 : *
3. Neutral 16 : **************** [3.5 +/- 0.7]
4. Agree 9 : *********
5. Strongly agree 3 : ***

III. Answer the following statements which may or may not describe
your beliefs about the use of flashcards in this class.

III.1 I like using flashcards.
1. Strongly disagree 0 :
2. Disagree 2 : **
3. Neutral 6 : ******
4. Agree 17 : ***************** [3.8 +/- 0.8]
5. Strongly agree 5 : *****

III.2 Flashcards helped me understand lectures better.
1. Strongly disagree 2 : **
2. Disagree 2 : **
3. Neutral 6 : ******
4. Agree 16 : **************** [3.6 +/- 1.1]
5. Strongly agree 4 : ****

III.3 I would recommend using flashcards in future semesters of Physics 205A.
1. Strongly disagree 1 : *
2. Disagree 1 : *
3. Neutral 5 : *****
4. Agree 17 : ***************** [3.9 +/- 0.9]
5. Strongly agree 6 : *******

III.4 I will avoid other classes using flashcards in future semesters.
1. Strongly disagree 11 : ***********
2. Disagree 12 : ************ [1.9 +/- 2.1]
3. Neutral 6 : ******
4. Agree 0 :
5. Strongly agree 1 : *

III.5 Flashcards were a positive experience.
1. Strongly disagree 1 : *
2. Disagree 1 : *
3. Neutral 3 : ***
4. Agree 20 : ******************** [3.9 +/- 0.8]
5. Strongly agree 5 :*****

III.6 Too much time in class was spent using flashcards.
1. Strongly disagree 2 : **
2. Disagree 14 : ************** [2.7 +/- 1.2]
3. Neutral 8 : ********
4. Agree 2 : **
5. Strongly agree 4 : ****

III.7 Too many flashcard questions were asked.
1. Strongly disagree 4 : ****
2. Disagree 17 : ***************** [2.3 +/- 1.0]
3. Neutral 6 : ******
4. Agree 3 : ***
5. Strongly agree 0 :

III.8 Using flashcards was difficult.
1. Strongly disagree 16 : **************** [1.5 +/- 2.9]
2. Disagree 14 : **************
3. Neutral 0 :
4. Agree 0 :
5. Strongly agree 0 :

IV. (Optional.) Please type in any comments you may have regarding
the use of flashcards in Physics 205A.
The following are all of the student responses to this question, verbatim and unedited.
"I Think The Flashcard System Is A Perfect Way To Get Introduced To And Move On To The Clickers."

"I liked the use of flash cards, besause they gave the instructor a good idea of where the class stood in understanding the material. as far the cards helping me understand the material that we were covering in class, well the flash cards weren't bad, but i would have liked the instructor to do more examples and demonstrations, not to mention explanations on the board."

"I thought using flash cards was very helpful. I think I need to spend more time doing the book problems and getting the anwsers to the clicker questions. Now I know what to look for through the class link."

"The flashcards are a great idea for interactive learning, however they did not influence the amount of content learned."

"The use of flashcards is helpful and good to use as a reenforcement of the lecture. However i think i personally need more lecture and explanations and problems thoroughly worked out and less flashcards rather than the majority of class being flashcards."

"Flashcards make me feel smart because i usually get the answers right. So, it makes class more rewarding for me"

"I've never had a class where the teacher lectured with clicker questions and flashcards. Maybe it will take me awhile to get used to it. I do feel as though I learn the most when I am doing the clicker questions and studying the textbook. I learn more when I study alone. I apologize for being harsh."

"Overall I understand why a teacher would use flashcards/clickers. It encourages students to listen, stay awake, talk to other students, ask questions from other students, etc., which is all positive. I personally can only learn when I see the problem completely worked out and would love to see more problems worked out on the board step by step. Even showing basic steps... This is how I process the best, but overall I enjoy the flashcards/clickers."

"flashcards and discussion with students is helpful, yet difficult for the shy"

"I think using flashcards is a great idea because it helps you to see if the class really understands a concept."

"I think that they are a great way to get everyone involved in the lecture"

"The flashcards seem to be the focus of this class, I was hoping for more lecture and explanation of the material we should be learning, during class time. A vast majority of my learning so far has been from reading the text. This is just a very different style of learning and teaching and I am going to do my best to adjust. I realize that most of the students seem to be more advanced in their math and this is where I need to freshen up."

"Overall I really like concept of flashcards and clickers to allow the teacher to get a general idea that the class is following the lecture and understands the material. However, I dislike using them so frequently, and would appreciate more actual lecture; you have to reach all types of learners."

"The flashcard use in this class, I believe, is very good. It kicks participation up 100%. In a standard lecture, maybe a few people are called on, but using flashcards gets everyone involved."

"The use of flashcards were fine so long as they don't distract from the overall lesson of the class session."

20090911

Physics clicker question: vector direction, from given components

Physics 205A, Spring Semester 2009
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 3.21 (extended)

Students were asked the following clicker question (Classroom Performance System, einstruction.com) at the start of their learning cycle:

The x- and y-components of a vector are given: A_x = +1.4 m, A_y = –5.7 m. What is the direction of this vector, as measured counterclockwise from the +x axis?
(A) +76°.
(B) +104°.
(C) +256°.
(D) +284°.
(E) (I'm lost, and don't know how to answer this.)

Sections 70854, 70855
(A) : 3 students
(B) : 2 students
(C) : 5 students
(D) : 19 students
(E) : 11 students

This question was asked again after displaying the tallied results with the lack of consensus, with the following results. No comments were made by the instructor, in order to see if students were going to be able to discuss and determine the correct answer among themselves.

Sections 70854, 70855
(A) : 0 students
(B) : 5 students
(C) : 2 students
(D) : 35 students
(E) : 1 students

Correct answer: (D)

The acute angle made by this vector with the x-axis is given by:

Arctan(A_y/A_x) = 76°,

which is not placed in the proper quadrant by most calculators; this must be done by inspection. From the fact that A_x is positive and A_y is negative, this vector is in the fourth quadrant, and thus the proper angle is 360° - 76° = +256, as measured counterclockwise with respect to the positive x-axis, as is done when using the unit circle in trigonometry.

Response (A) is the raw answer from Arctan(A_y/A_x), response (B) is 180° - 76°, while response (C) is 180° + 76°.

Note that from inspection, response (D) is the only vector angle that is in the fourth quadrant, and thus can be deduced as the correct angle without explicitly doing any calculations.

Pre- to post- peer-interaction gains:
pre-interaction correct =48%
post-interaction correct = 81%
Hake, or normalized gain = 65%

20090910

Astronomy current events question: Jupiter impact aftermath

Astronomy 210L, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Kelly Beatty, "Jupiter's Impact: Gone in 30 Days," August 27, 2009
http://www.skyandtelescope.com/news/53952917.html
What has happened to the new dark spot on Jupiter caused by a recent impact?
(A) Large enough to affect Jupiter's weather patterns.
(B) Changed from dark brown to red.
(C) Split into two small dark spots.
(D) Nearly disappeared.
(E) Moved to Jupiter's north pole.

Correct answer: (D).

Student responses
Sections 70178, 71086
(A) : 5 students
(B) : 3 students
(C) : 1 student
(D) : 34 students
(E) : 1 student

20090909

Astronomy current events question: hot exoplanet WASP-18b

Astronomy 210L, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)
Kelly Beatty, "Why Does Exoplanet WASP-18b Exist?" August 26, 2009
http://www.skyandtelescope.com/news/55066637.html
According to United Kingdom researchers, what is so surprising about the recently discovered exoplanet WASP-18b?
(A) Orbits its star too closely to survive very long.
(B) Has traces of organic compounds associated with life on Earth.
(C) May have recently collided with exoplanet WASP-18a.
(D) Too large to be considered a planet.
(E) Will soon cause its star to undergo a nova explosion.

Correct answer: (A).

Student responses
Sections 70178, 71086
(A) : 34 students
(B) : 3 students
(C) : 6 students
(D) : 1 student
(E) : 0 students

20090908

Online reading assignment question: opinions towards astrology

Astronomy 210, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

(The following question was asked subsequent to, and then again following the lecture discussing the basis of sun-sign astrology, and how precession has shifted the position of the sun within certain zodiac constellations by one month from the dates published in popular astrological horoscopes.)

I believe astrology is able to make accurate predictions about my future. (Graded for completion.)
(SD) Strongly disagree.
(D) Disagree.
(N) Neutral.
(A) Agree
(SA) Strongly agree.

Student responses (pre-instruction)
Sections 70158, 70160
(SD) : 17 students
(D) : 16 students
(N) : 27 students
(A) : 8 students
(SA) : 0 students

Student responses (post-instruction)
Sections 70158, 70160
(SD) : 17 students
(D) : 18 students
(N) : 26 students
(A) : 7 students
(SA) : 2 students

Of the 68 students who had answered the pre-instruction question, and the 70 students who had answered the post-instruction question, 49 students had answered both the pre- and post-instruction questions (while 19 students answered only the pre-instruction, and 21 students only answered the post-instruction question).

Of the 49 students who answered both the pre- and post-instruction questions, 34 students had no change in their opinion, while 15 students changed their opinion.

Student responses (pre- and post-instruction responders, no change in opinion, N = 34)
Sections 70158, 70160
(SD) : 9 students
(D) : 8 students
(N) : 14 students
(A) : 3 students
(SA) : 0 students

Student responses (pre- and post-instruction responders, change in opinion, N = 15)
Sections 70158, 70160
(SD) : pre: 2 students; post: 4 students
(D) : pre: 6 students; post: 6 students
(N) : pre: 5 students; post: 4 students
(A) : pre: 2 students; post: 1 student
(SA) : pre: 0 students; post: 0 students

A Student t-test on all 49 students who answered both the pre- and post-instruction questions (34 students with no change in their opinion together with the 15 students that changed their opinion) results in p = 0.60, and thus there is no statistically significant difference between pre- and post-instruction responses.

For the students who took both and responded differently to the pre- and post-instruction questions, here were the shifts:

(SD) to (D): 2 students
(D) to (SD): 3 students
(D) to (N): 3 students
(N) to (SD): 1 student
(N) to (D): 3 students
(N) to (A): 1 student
(A) to (D): 1 student
(A) to (N): 1 student

"Negative shifts" in opinion (e.g., towards disagreement): 9 students
"Positive shifts" in opinion (e.g., towards agreement): 6 students
(Compare with the 34 students with no shifts in opinion.)

It appears that there is only a very slight shift towards negative opinions towards astrology in this small population sample, as many students apparently already have strongly held positions on this matter that are not going to be affected much by a single lecture on the basis of sun-sign astrology on Earth's revolution about the sun.

Students were given the opportunity to explain their pre-instruction opinion, responses are listed below verbatim.

Briefly explain your answer regarding your belief/disbelief in astrology. (Graded for completion.)
"i was raised catholic and i am not supposed to believe in astrology but i think that a lot of answers are amongst the stars."

"I believe that Jesus Christ is my Lord and Savior and only he can "predict" my future. :D"

"I check my horoscope everyday and sometimes it is accurate and other times it is off so I do believe it can be true at times."

"I believe that the day you were born does not serve as a credible indication of things, happenings, and/or events that will happen in your life."

"I just don't buy it. I put it in the same catagory as fortune cookies. they can apply to anybody."

"I find the information about astrology very interesting. Something i can relate to, but i usually don't take it word for word."

"There's no way the stars can predict how a person acts, because there are so many people and they are all different from eachother"

"I am a Leo and I agree on my traits. But i am not sure on the accuracy because i never really followed it it would have to be proven to me."

"I do not have a great deal of experience with astrology, but in my opinion it is the kind of thing that only works if you believe in it. Most horoscopes are general enough that they could apply to anybody, and like fortune cookies sometimes contain predictions that may or may not come true. As far as astrological signs and personalities go, I do believe that one's sign can contribute to their persona. This may be, though, due more to the environment in which that person was raised than to the exact date of his or her birth.
there have been lots of times where i have read my horoscope and it has describes a situation im going through, or it has suggested at events that are current in my life at that particular time."

"I've been told a lot of accurate things about personality traits from astrology, but I haven't heard anything about the future that's been correct.
I honestly think that it could go either way, astrology could be false or there could be some truth to it."

"i think we can trust astrology. we can use it to know many things.
I'm not entirely sure one way or the other."

"I dont understand how positions in the stars relate to our actions on earth."

"I dont think the time and date and stars on your birthday has any determination in your future. Though knowing some zodiac signs and meanings, the scorpio clears describes me to the t. So I am most defintely neural."

"Im not one that is really into astrology but i believe it. I am a scorpio and quite honestly i can be obsessive and sensitive but also i am a little crazy and scorpions are so i believe it."

"I agree for the fact, i'm gonna walk north sometime and look up at the north star to find my way out of the jungles of zanzabar."

"dont know how i feel about it, all new too me, come in with and open mind.
I believe in horoscopes, zodiac signs and that astrology is a genuine way of thinking that most people deny."

"Because I am a christian and i don't believe in astrology. i believe the stars were created by God and he is in control of everything."

"Astrology, aside from using vague and common traits to describe people striving for an identity so fervently that they look up rather than inside themselves, is completely reliant on these followers to prove it's predictions to be true. That is to say, astrology will always be right because the people who believe in it want it to be right, and those who don't care about astrology (who is legion, for they are many), also don't care enough to disprove it. Astrology is a complex system reliant on it's complexity to convince people of it's veracity, and believed by those so deeply frightened of the unknown, unpredictable future, that they will believe anything that reassures them they will live to see another day."

"I believe I can help decide what happens in my future. Astrology will not change or make any of my future decisions."

"I really dont think that astrology is that great at predicting things but sometimes it is true. Predictions are somehthing that dont really effect me and i dont really pay attention to them."

"I feel that astrology often offers very vague descriptions of what will happen 'according to the stars' in order to make the prediction easily applied to things that actually happen. Astrology is too broad to produce exact insight to the future."

"not only do i hold religious beliefs but i have read studies on it and it has been proven false. i do not believe it is evil or a sin to read your horoscope but do not believe it is true."

"I believe, when done correctly, Astrology can be a very accurate way to observe the possible pathways people can take during life."

"I am neutral because I don't pay any attention to astrology. I have never used it to make predictions about my future."

"I think it's a total load of hooey. I know astronomy, like the rest of everything around us, plays a role on how we act etc., but astrology is ridiculous. People are like ooh you're a scorpio you won't go well with a taurus, i'm like both my girlfriends i dated for over two years have both been Taurus's shut up and put your belief in something that's actually not ridiculous. All zodia things i've read are wrong 100% more than they're right. and they're always so vague too"

"Its never really proved to mean anything in my life."

"'Do not learn the ways of the nations or be terrified by signs in the sky, though the nations are terrified by them' (Jeremiah 10:1-2). God knows the future. I choose not to be dictated by anything else. Though he may use the stars."

"I never really look into those type of beliefs other than what the astrological meaning of my sign and others mean to see if they are true or not. More so, all of it is for fun."

"I'm not too sure i'm just neutral on it! very interesting!"

"I believe that astrology can help people predict the future if everything is played out in its natural course. Every person obviously can make their own choices and act how they want, but I do think that the stars and cosmic bodies can influence predictions."

"I believe astrology could possibly make accurate predictions about my future but, I don't believe the predictions are common or exact."

"Because sometimes the things listed in horoscopes don't happen as depicted."

"i dont really know what to think just yet just reading the descriptions of the zodiac signs make it seem believable so i will have to wait and find out"

"The future is unwritten and nothing can predict the future. Time is like a river with an infinite number of branches downstream, no one knows what branch they're going to go down."

"I believe astrology can make accurate predictions about the Earth's future, but not my personal life."

"I used to beleive in it, until i realized that we all do and don't share some of descripions."

"As far as I've seen, the predictions made for a person based on their starsigns are very broad, and often do not occur. I'm not a superstitious person, and all of the above descriptor words for each starsign could be applied to myself, depending on how I looked at it."

"In my experience with astrology, it's predictions and explanations of the future have seemed vague and adaptable, so as to apply to almost anyone."

"Astrology may get a lucky break and guess correctly every once in a while, but to me it seems to be mostly fantasy that the movements of the stars somehow predict the future."

"most the time it is true for me personally"

"I don't believe that when I was born or how the stars are aligned can tell me my future."

"Astrology has zero credibility to me. People see what the want to see and believe what the want to believe. If someone wants astrology to be credible they can tie it into their everyday lives. I don't. I still look at my astrology sign because it is fun to see what is predicted for your sign. Just curiosity I suppose, similar to wanted to see what lies inside a fortune cookie. You read, but don't take it seriously."

"I just don't believe that the stars can make predictions about my future."

"I believe that God has my future planned out, and that he did not that he put the answers in the stars because we need to trust him."

"I have heard both views that it can or cant accurately predict my future and I am not sure of either answer."

"I am not totally convinced about our signs but it does seem like a lot of the time it is correct"

"I disagree because I have yet to read or hear an accurate prediction on my future. Heck, I'm a pisces and half the description of that is incorrect.
Astrology is a pseudoscience, it may be fun but it is not scientifically proven"

"it depends on the predictions....it doesnt control my decisions."

"I don't know enough about astrology to either agree with it, or disagree, therefore I'm staying neutral in my answer."

"I am Neutral about astrology because I am a believe in Christ. And in the Bible it says that Christians should not believe in the make believe. That God plans your future and he's the only one that knows it fully. However, God made the universe, so he made the stars. It also is fun to look up your Horoscope and see what teen magazines have to say."

"i think that God is the only one that can make predictions in my life, for he is the one that gave us life."

"i believe that firstly if astrology were at all accurate it would not be the study of an aspect of the heavens which could predict my future but the stars themselves, or the person studying them. secondly if the stars show my life in any of their aspects i do not believe that humans know enough to be able to predict it. If God exists (and in my personal opinion He does) He could if he so desired tell me my fortune by looking at the stars, but He is omniscient and would have no such need of such an obscure source."

"well i allways thought that astronomy was bullshit. THEN i watched an episode of "Penn and Teller's Bullshit" on the armagedon and astronomy and decided astronomy is void."

"Im not really sure about how i feel because the charts and stuff describe my relationship with my friends pretty well but i just find it hard to believe in something like that."

"I believe that astrology is not that accurate, however I think that there are some things that are true. Such as some of the descriptions for the sins of the zodiac"

"I was raised that only god has the power to know what our future holds, but I beleive life is always changing and that there is not set way of life so astrology could not pin point a future that's constantly changing."

"I read my horoscope everyday and it sometimes pertains to my life but I don't think it can predict my future. I think our actions guide what happens to us and that astrology has a lot to do with superstition."

"I don't think the stars have any relation to people's future, personality, etc. depending on their birthdate. Astrology isn't always right and gets too general."

"I just believe that i am the only person who can change my future so no one or nothing can tell my future."

"i chose neutral because i'm not sure wether or not it can make accurate predictions about my future. it seems silly to believe it can, but i don't want to say it doesn't."

"I don't think the same prediction based on stars could beapplied to eveyone born in a certain time period and be accurate."

"I am a believer in God and I believe that He has my future in his hands."

"i don't really see how the alignment of the stars when a person was born has any affect on personality."
There was one unsolicited student comment after the sun-sign astrology lecture:
"I found my sign to be more accurate when looking at the month before, like you said in class. Very interesting."
References:
  • A. Fraknoi, ed., "The Universe At Your Fingertips: An Astronomy Activity
    and Resource Notebook," Astronomical Society of the Pacific, p. K-2, 1995.
    (http://www.astrosociety.org/education/astro/act3/astrologyprint.html)
    "Clearly, those of us who love astronomy cannot just hope that the public's infatuation with astrology will go away. We must speak out whenever it is useful or appropriate--to discuss the shortcomings of astrology and the shaky ground it is based on. Those of us working with youngsters can use these ideas to develop a healthy skepticism in the students and encourage an interest in the real cosmos--the one of remote worlds and suns that are mercifully unconcerned with the lives and desires of the creatures on planet Earth. Let's not allow another generation of young people to grow up tied to an ancient fantasy, left over from a time when we huddled by the firelight, afraid of the night."

  • H. Kuglak, "Deprogramming Student Attitudes Toward Astrology," The Physics Teacher, vol. 16, no. 3, pp. 165-167 (March 1978).
    "Nearly one-quarter of the students believed in astrology at the start of the semester... There were significantly higher percentages of female than male believers at the beginning of the courses..."
          "The study indicates that some deprogramming of student attitudes towards astrology is possible. However, it would be much more difficult to prove that there was a behavior modification."
          "There were 97% of the polled students who knew their zodiacal sign; the percentage at the end of the semester was 98%. As the course instructor, I decline any credit for the 1% increase!"

  • M. C. LoPresto, "Tolerance for Astrology?" Astronomy Education Review, vol 1, no. 2, p. 125 (2003).
    (http://aer.noao.edu/cgi-bin/article.pl?id=41)
    "When is your birthday? Find your birthday on the ecliptic. Name the constellation the Sun is in or closest to on your birthday. Now compare how the Sun's location corresponds to the current astrological or zodiac signs for each date."

20090907

Astronomy quiz question: Virgo setting

Astronomy 210 Quiz 1, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Consider the view of the horizon shown below, as seen from San Luis Obispo, CA at a certain time on September 2. Ignore the fact that your starwheel does not include daylight savings time. Assume that you are able to see these constellations regardless if the sun is above the horizon or not.

How many hours pass until Virgo sets completely below the horizon?
(A) Three hours.
(B) Seven hours.
(C) 11 hours.
(D) 24 hours.

Correct answer: (C)

Using a starwheel, where the view shown above corresponds to 11:00 AM on September 2, Virgo will set on the west horizon at 10:00 PM, which is 11 hours later.

Response (A) corresponds to the hours for Virgo to completely set below the west horizon, starting from being just above the west horizon on September 2 (7:00 AM).

Section 70158
(A) : 11 students
(B) : 7 students
(C) : 32 students
(D) : 2 students

Success level: 64% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.72

20090906

Astronomy quiz question: wee hours moon/afternoon moon

Astronomy 210 Quiz 1, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

[Version 1]

Which phase will the moon be in if it is highest overhead at 3:00 AM? Clearly circle your answer below.

Correct answer: (G) (Waning gibbous)

Section 70158
(A) : 3 students
(B) : 2 students
(C) : 3 students
(D) : 1 student
(E) : 5 students
(F) : 0 students
(G) : 11 students
(H) : 0 students

[Version 2]

Which phase will the moon be in if it is highest overhead at 3:00 PM? Clearly circle your answer below.

Correct answer: (C) (Waxing crescent)

Section 70158
(A) : 0 students
(B) : 3 students
(C) : 18 students
(D) : 1 student
(E) : 1 student
(F) : 0 students
(G) : 1 student
(H) : 0 students

Success level: 58% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.59

20090905

Astronomy quiz question: moonrise and moonset

Astronomy 210 Quiz 1, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

What causes the moon to rise and set?
(A) Earth's rotation.
(B) Earth's revolution.
(C) Earth's precession.
(D) Earth's tilt.

Correct answer: (A)

Over one day, the position of the moon in its orbit relative to Earth remains approximately the same, while the rotation of Earth about its axis makes the moon appear to rise and set, along with the stars and the sun in their diurnal motion across the celestial sphere.

Section 70160
(A) : 35 students
(B) : 3 students
(C) : 2 students
(D) : 2 students

Success level: 83% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.46

20090904

Astronomy quiz question: circumpolar constellations

Astronomy 210 Quiz 1, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Consider the view of the horizon shown below, as seen from San Luis Obispo, CA at a certain time on September 1. Ignore the fact that your starwheel does not include daylight savings time. Assume that you are able to see these constellations regardless if the sun is above the horizon or not.

According to your starwheel, what time corresponds to the view shown above?
(A) 7:30 AM.
(B) 10:30 AM.
(C) 7:30 PM.
(D) 10:30 PM.

Correct answer: (C)

With the north horizon of the starwheel oriented downwards, placing Ursa Major and Cassiopeia to the left and right of Polaris respectively, as shown, results in September 1 on the dial lining up with 7:30 PM on the edge of the starwheel.

Response (A) is with Cassiopeia and Ursa Major switching positions, to the right and left of Polaris, respectively.

Section 70160
(A) : 9 students
(B) : 0 students
(C) : 33 students
(D) : 0 students

Success level: 78% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.54

20090902

Physics quiz question: banana slug speed

Physics 205A Quiz 1, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 1.25

The speed of a large banana slug (http://hypertextbook.com/facts/AngieYee.shtml) has been timed at 0.0023 cm/s. What is this speed in miles per hour? There are 1,609 m in one mile.
(A) 4.0e-8 mi/hr.
(B) 5.1e-5 mi/hr.
(C) 8.6e-5 mi/hr.
(D) 1.0e-3 mi/hr.

Correct answer: (B)

To convert cm/s into mi/hr:

(0.0023 cm/s) * (1 m/100 cm) * (1 mi/1,609 m) * (3,600 s/1 hr) = 5.1e-5 mi/hr.

Response (A) is 0.0023*100/(3,600*1,609); response (C) is 0.0023*60/1,609; response (D) is 0.0023*1,609/3600.

Student responses
Sections 70854, 70855
(A) : 3 students
(B) : 43 students
(C) : 9 students
(D) : 0 students

Success level: 78%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.91

20090901

Physics quiz question: area factor increase

Physics 205A Quiz 1, Fall Semester 2009
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problems 1.11, 1.12

[Version 1]

An architect is redesigning a rectangular doorway. She decides to double the width of the doorway, and increase the height by 50%. By what factor has the area of the doorway increased?
(A) 1.0
(B) 1.5.
(C) 2.5.
(D) 3.

Correct answer: (D)

The original and new areas A in terms of the original and new widths w and heights h of the doorway are given by:

A_1 = w_1*h_1,
A_2 = w_2*h_2.

The new width and new height, in terms of the original width and height are given by:

w_2 = 2.0*w_1 ("doubled"),
h_2 = 1.50*h_1 ("increased by 50%).

Thus the new area, in terms of the original area is:

A_2 = h_2*w_2 = (2.0*w_1)*(1.50*h_1) = 3.0*w_1*h_1 = 3.0*A_1,

corresponding to an increase by a factor of 3.0.

Response (A) is 2.0*0.50 (the result of which, strangely enough, would correspond to a new doorway that has the same area as the original doorway, despite the increases in width and height). Response (B) is the result of 2.0 - 0.50; and response (C) is 2.0 + 0.50.

Student responses
Sections 70854, 70855
(A) : 5 students
(B) : 7 students
(C) : 11 students
(D) : 32 students

Success level: 58%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.65

[Version 2]

An architect is redesigning a rectangular doorway. She decides to increase the width of the doorway by 40%, and increase the height by 25%. By what factor has the area of the doorway increased?
(A) 0.100.
(B) 1.10.
(C) 1.70.
(D) 1.80.

Correct answer: (D)

The new width and new height, in terms of the original width and height are given by:

w_2 = 1.40*w_1 ("increased by 40%"),
h_2 = 1.25*h_1 ("increased by 25%).

Thus the new area, in terms of the original area is:

A_2 = h_2*w_2 = (1.40*w_1)*(1.25*h_1) = 1.80*w_1*h_1 = 1.80*A_1,

corresponding to an increase by a factor of 1.80.

Response (A) is the result of 0.40*0.25; response (B) is (1+ 0.40*0.25); and response (C) is (1+ 0.40 + 0.25).

Student responses
Section 72177
(A) : 3 students
(B) : 1 student
(C) : 2 students
(D) : 9 students

Success level: 60%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.37