Grader Plug-ins
If the final answer is correct, then the problem is given full credit and a message is generated to that effect. Otherwise, partial credit is given for previous parts.
We need a special problem grader on this problem, since we want the student to get full credit for all five answers correct, 60% credit for four correct, and 0% for three or fewer correct. To change this scheme, look through the following mess of code for the place where the variable $numright appears, and change that part. Also change the long line beginning "msg ==>", to show what will appear on the screen for the student.
To look at the problem itself, look for the boxed comment below announcing the problem itself.
This problem grader custom_problem_grader_fluid was contributed by Prof. Zig Fiedorowicz, Dept. of Mathematics, Ohio State University on 8/25/01. As written, the problem grader should be put in a separate macro file. If actually inserted into a problem, you need to replace a couple of backslashes by double tildes.
This is a generalization of the previous custom grader. This grader expects two array references to be passed to it, eg. $ENV['grader_numright'] = [2,5,7,10]; $ENV['grader_scores'] = [0.1,0.4,0.6,1] Both arrays should be of the same length, and in strictly increasing order. The first array is an array of possible raw scores, the number of parts of the problem the student might get right. The second array is the corresponding array of scores the student would be credited with for getting that many parts right. The scores should be real numbers between 0 and 1. The last element of the 'grader_scores' array should be 1 (perfect score). The corresponding last element of 'grader_numright' would be the total number of parts of the problem the student would have to get right for a perfect score. Normally this would be the total number of parts to the problem. In the example shown above, the student would get 10% credit for getting 2-4 parts right, 40% credit for getting 5-6 parts right, 60% credit for getting 7-9 parts right, and 100% credit for getting 10 (or more) parts right. A message to be displayed to the student about the grading policy for the problems should be passed via $ENV{'grader_message'} = "The grading policy for this problem is..."; or something similar.