A Web-based Automatic Program Grader Don Colton, Leslie Fife, Andrew Thompson School of Computing Brigham Young University Hawaii

Order of Presentation Motivation/Rationale GradeBot Discussion WebBot Improvements Observed Results Conclusions/Future Work

Motivation/Rationale Ability to program – critical tool Pace of assignments difficult for beginning students Beginners need more and smaller steps Beginners need rapid feedback Grading Burden Introduced Large Classes More assignments with fast feedback Perfect Programs Paradigm

GradeBot Grading Model Infinite Loops Handled Core Dumps Eliminated Submit programs in any supported language Automated Test Case Creation Comparison to expected output Expected results (with test case) returned for debugging Infinite Loops Handled Core Dumps Eliminated New Lab Creation Simplified

WebBot Adds a User Interface to GradeBot Simplify the Editing/Submission Process to decrease startup time for new students. Postpone the challenge of learning new tools (Emacs, IDEs, etc.)

WebBot Login

WebBot Workspace (frames)

WebBot Status Report

WebBot Options Page

WebBot Discussion IDE Introduction not prevented only delayed Cheating

Table I: WebBot Submission History Observed Results Table I: WebBot Submission History Year 2004 2005 Course CS 1 CS 2 Algorithm Analysis Students 175 133 19 169 117 42 Submits (purged) 73405 15043 5684 Success 6995 1007 189 6518 767 385 Success % 8.9% 5.1% 6.8%

Conclusions/Future Work Does Not Handle Style not graded Cannot provide detailed help in all cases Does Handle Large number of Requests Perfect Programming Paradigm Open Entry/Open Exit Next: Instructor Interface Module

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