I happily use the exam document class to create exams and quizzes. I often make at least part of my exams multiple choice, and I'd like to be able to

1. generate multiple versions of the exam by permuting the answer choices (automatically, rather than by hand as I do now), and
2. generate an answer key for each version when compiling the exam with answers on.

Do any of you do that or have suggestions about how I might be able to implement that?

-
Welcome to tex.sx! It's not necessary to sign your questions (as there is already a box with your username below it) or to begin them with a greeting. –  Thorsten May 11 '11 at 14:25
Thanks for the tips! –  Jason May 11 '11 at 14:30

I know this problem well. I have my own package that does it, along with several documents full of crufty code. I can tell you my implementation:

• Use a pgfmath list to store the answer choices
• Do a Knuth shuffle on that list to permute them
• Walk over the list printing out each choice

You might find the \pgfmathsetseed command useful because you want randomized choices but the same randomized choices each time you compile! You might also find http://random.org/ good for getting sufficiently random seeds.

For generating multiple versions and answer keys I use docstrip. My main file is a docstrip file like exam.dtx and I use guards like

%<A>\pgfmathsetseed{1001} % seed for A version
%<B>\pgfmathsetseed{1010} % seed for B version
%<*key>
% commands that alter whether the key is shown
%</key>


to \generate files like exam-A.tex, exam-A-key.tex, etc. Then you have one document per file without manually repeating code.

I don't use the exam class but I think this could work in that.

-
Thanks Matthew - very helpful! –  Jason May 12 '11 at 16:42

In ConTeXt, the itemize environment (which is equivalent to LaTeX's itemize and enumerate) supports a random key. So, to get random permutation of options use. But, you have to use \startitem ... \stopitem instead of \item to capture the items.

\starttext

\startitemize[n,random]
\startitem First item \stopitem
\startitem Second item \stopitem
\startitem Third item \stopitem
\stopitemize

\stoptext


I haven't checked how good the randomizing algorithm is. You could, of course, implement this in LuaTeX very easily. (The ConTeXt solution predates lua, and is implemented in eTeX)

-
Thanks Aditya - very intesting - I'm not at all familiar with ConTeXt, but it's very cool that itemize has a random key. Now I'm curious to look into it. –  Jason May 12 '11 at 16:44

You can also use the automultiplechoice package from AMC software, which also allows to get the marks from the completed answer sheets scans.

-

Although this is a relatively old question, a possible answer, without the use of any packages or classes, is described here. It relies on Python and a little bash scripting to produce the different versions. Questions and their possible answers are automatically shuffled in each version, and the key is printed at the end of the produced tex files (after the \end{document}).

-