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Evaluating the Effectiveness of Feedback in SQL-Tutor. Antonija Mitrovic, Brent Martin Intelligent Computer Tutoring Group Computer Science Department University of Canterbury Christchurch, New Zealand. Overview. SQL-Tutor Feedback types Evaluation study Results.
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Evaluating the Effectiveness of Feedback in SQL-Tutor Antonija Mitrovic, Brent Martin Intelligent Computer Tutoring Group Computer Science Department University of Canterbury Christchurch, New Zealand
Overview • SQL-Tutor • Feedback types • Evaluation study • Results
SQLT-Web: a Web-enabled SQL tutor • http://ictg.cosc.canterbury.ac.nz:8000/sql-tutor/ • Interface developed in CL HTTP-server • Used in COSC courses since 1999 • Open for outside users on March 29, 2000
Feedback types • Positive/negative • Error flag • Hint • All errors • Partial solution • Complete solution
Hypothesis: • Positive/negative and Error flag too general • Low-level feedback contraproductive (partial and complete solution) • Constraint-based feedback most effective (hint and all errors)
Evaluation study • COSC313, May 1999 (Web) • Single 2-hour session • 6 lectures + 8 hours of labs • 33 students
Three groups: • Detailed (complete and partial solution) • General (hint and all errors) • Limited (pos/neg and error flag)
Results 1 Difference in times is significant
Initial learning rate • All errors 0.44 • Error Flag 0.40 • Pos/Neg 0.29 • Hint 0.26 • Partial 0.15 • Full solution 0.13
Conclusions • General feedback is most effective • Detailed feedback is detrimental to learning • Feedback level needs to be adapted