edx/edx-platform — pull request #2721 by rocha (2014-02-25 19:54:26+00:00)
Title: Add map to problem_check event with descriptions of student answers

The map contains a human readable description of the answer if
necessary. It is useful for problem like multiple choice, when the
response of the student is replaced by a moniker. For example "choice_0"
instead of the full text.