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ERIC Number: ED440134
Record Type: Non-Journal
Publication Date: 2000-Feb
Pages: 62
Abstractor: N/A
Reference Count: N/A
Accuracy of Individual Scores Expressed in Percentile Ranks: Classical Test Theory Calculations. CSE Technical Report.
Rogosa, David
In the reporting of individual student results from standardized tests in educational assessments, the percentile rank of the individual student is a major numerical indicator. This paper develops a formulation and presents calculations to examine the accuracy of the individual percentile rank score. Here, accuracy follows the common-sense interpretation of how close one comes to the target. Calculations are presented for: (1) percentile discrepancy (the difference between the percentile rank of the obtained test score compared to perfectly accurate measurement); (2) comparisons of a student score to a standard (e.g., national norm 50th percentile); (3) test-retest consistency (difference between the percentile rank of the obtained test score in two repeated administrations; and (4) comparison of two students (difference between the percentile rank of the obtained test scores for two students of different achievement levels.) One important theme is to compare the results of these calculations with the traditional interpretations of the test reliability coefficient; e.g., whether high reliability implies good accuracy. (Contains 18 tables, 33 figures, and 9 references.) (SLD)
Center for the Study of Evaluation, National Center for Research on Evaluation Standards, and Student Testing, Graduate School of Education & Information Studies, University of California at Los Angeles, 300 Charles E. Young Dr. North, Los Angeles, CA 90095-1522 ($5.50). Tel: 310-266-1532. For full text:
Publication Type: Numerical/Quantitative Data; Reports - Descriptive
Education Level: N/A
Audience: N/A
Language: English
Sponsor: Office of Educational Research and Improvement (ED), Washington, DC.
Authoring Institution: California Univ., Los Angeles. Center for the Study of Evaluation.; Center for Research on Evaluation, Standards, and Student Testing, Los Angeles, CA.