The purpose of this study was to investigate the extent to which written error-correcting feedback on teacher-made criterion-referenced tests results in increased achievement of high school students taking algebra. In addition, student attitudes toward chapter tests and changes that may occur in those attitudes resulting from teacher treatment of tests was considered. Two classes of algebra students were used, one being the control group and the other, the experimental group. Students in the control group received their usual treatment of tests at the end of each chapter, and test papers were returned with incorrect responses marked wrong and a test grade. The incorrect responses were discussed both in and out of class with the teacher. All students in the experimental group received the same treatment as the control group. In addition, they were provided with written, error-correcting feedback on their examination papers. This feedback included "free comments" (e.g. words of encouragement and compliments for creative solutions). The findings showed no significant connection between the feedback provided and increased achievement. Possible reasons for this result included the inability to control extraneous variables, and the lack of validity and reliability of the tests used. A 41-item reference list and a student survey instrument are included. (TW)