Astronomy clicker question: extremely young cluster stars

Astronomy 210, Fall Semester 2008
Cuesta College, San Luis Obispo, CA

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

__________ will be found in an extremely young star cluster.
(A) Supergiants.
(B) Red dwarfs.
(C) White dwarfs.
(D) Blue-hot main sequence stars.
(E) Yellow-hot main sequence stars.
(F) (More than one of the above choices.)
(G) (I'm lost, and don't know how to answer this.)

Section 70158 (pre-)
(A) : 20 students
(B) : 6 students
(C) : 6 students
(D) : 5 students
(E) : 2 students
(F) : 4 students
(G) : 0 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.

Section 70158 (post-)
(A) : 0 students
(B) : 6 students
(C) : 6 students
(D) : 22 students
(E) : 5 students
(F) : 4 students
(G) : 0 students

Correct answer: (D)

Massive stars (blue-hot main sequence stars, which become supergiants) evolve faster than medium mass stars (yellow-hot main sequence stars, which become giants, then white dwarfs), which evolve faster than low mass stars (red dwarfs). Thus blue-hot main sequence stars will be the youngest type of stars, and be found in extremely young stars clusters.

Pre- to post- peer-interaction gains:
pre-interaction correct = 12%
post-interaction correct = 51%
Hake (normalized) gain <g> = 45%

Section 70160 (pre-)
(A) : 10 students
(B) : 2 students
(C) : 0 students
(D) : 4 students
(E) : 1 student
(F) : 9 students
(G) : 0 students

Section 70160 (post-, after students were directed to not pick (F))
(A) : 20 students
(B) : 1 student
(C) : 5 students
(D) : 5 students
(E) : 0 students
(F) : 0 students
(G) : 0 students

Pre- to post- peer-interaction gains:
pre-interaction correct = 15%
post-interaction correct = 16%
Hake (normalized) gain <g> = 1%