Education research: introductory astronomy midterm statistics

Cuesta College Astronomy 210 (introductory astronomy lecture) students take their second midterm on spectra, stars, galaxies and cosmology in the fourteenth/fifteenth week of instruction.

The midterm consists of ten multiple-choice questions (with partial credit for multiple-choice), and three short-answer questions (graded with a standardized rubric), to be completed within 80 minutes (the length of a regularly-scheduled lecture).

Grading statistics:

Cuesta College
Astronomy 210 fall semester 2011 section 70158
Midterm 2 results (N = 34, maximum possible score = 100):
   0- 20.0 :   
20.5- 40.0 : **  [low = 38.0]
40.5- 60.0 : *************
60.5- 80.0 : *********  [mean = 66.1 +/- 16.9]
80.5-100.0 : **********  [high = 96.5]

One student was excluded from the linear regression due to taking the midterms at other scheduled times (and thus was not ordered with the rest of the class). With a linear regression r² value of 0.0296, there is no significant correlation between the completion order c turning on the midterm and resulting score S (S = 0.2791c + 61.108).


Grading statistics:

Cuesta College
Astronomy 210 fall semester 2011 section 70160
Midterm 2 results (N = 28, maximum possible score = 100):
   0- 20.0 :   
20.5- 40.0 : **  [low = 39.0]
40.5- 60.0 : *****
60.5- 80.0 : ************  [mean = 70.8 +/- 16.9]
80.5-100.0 : *********  [high = 96.0]

Four students were excluded from the linear regression, two from clerical errors in recording their completion order, and two due to taking the midterms at other scheduled times (and thus were not ordered with the rest of the class). With a linear regression r² value of 0.0562, there is no significant correlation between the completion order c turning on the midterm and resulting score S (S = 0.532c + 66.663).