When determining criterion-referenced test length, problems of guessing are shown to be more serious than expected. A new method of scoring is presented that corrects for guessing without assuming that guessing is random. Empirical investigations of the procedure are examined. Test length can be substantially reduced. (Author/CM)

This study compared the reliability and validity indexes of randomly parallel tests administered under inclusion, exclusion, and correction for guessing directions, using 54 graduate students. It also compared the criterion-referenced grading decisions based on the different scoring methods. (TJH)

Six methods of scoring multiple true-false items were compared in terms of reliabilities, difficulties, and discrimination. Results suggest that, for norm-referenced score interpretations, there is insufficient evidence to support any one of the methods as superior. For criterion-referenced score interpretations, effects of scoring method must be…