Additionally, Agar represents a significant advancement over previous attempts in that it also has shown greatly reduced effort required to grade non-programming material such as written work and quizzes, and can be incorporated with an Optical Mark Recognition system that was also developed at UCR. The automated-testing features of Agar make it ideal for grading programming work of all kinds, but the real benefit comes from the time-savings for human graders in providing detailed feedback. Additionally, Agar is open source and is written in an interpreted language, so anything that isn't handled by the tool interface can be added to the system internally.
Agar addresses consistency and grader efficiency together. The first time a human grader using Agar finds a problem with a student submission that wasn't automatically detected (or even tested for), they create a new comment, assign a point value (positive for bonus, zero to just write a comment, and negative for penalty) to the comment, and write out a note to the student. A drag-and-drop system within the Agar interface then allows that comment to be assigned to any other student that is found to have the same mistake. Further, since comments are assigned by reference, the point value or feedback can be changed later on, and all submissions that received that comment will automatically be updated.
This comment system allows for much greater feedback to be generated for each student in a much shorter amount of time. For C++ homework in our lower-division courses, a two-week project for a class of 60-70 students now takes about 4-6 hours to grade, to record scores, and to generate and send out detailed feedback for students. Previously, lower quality feedback and less accurate grading took at least 10-15 hours. Similarly, 12 written problems for the same course were graded and commented in just under 5 hours, or slightly less than 5 minutes per student. Students in this course have how helpful they find it to get their work returned to them within 1-2 days of turning it in, and have detailed comments and feedback emailed to them while they still remember what the assignment involved. Graders are similarly pleased in that they get to do more in less time, and no longer have any bookkeeping to do since Agar can automatically exports its results to a course grade-book in the form of a spreadsheet.