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SOME RESULTS RELATING TO TEST EQUATING UNDER RELAXED TEST FORM EQUIVALENCE
Author(s) -
MARKS EDMOND,
LINDSAY CARL A.
Publication year - 1972
Publication title -
journal of educational measurement
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.917
H-Index - 47
eISSN - 1745-3984
pISSN - 0022-0655
DOI - 10.1111/j.1745-3984.1972.tb00760.x
Subject(s) - equating , equivalence (formal languages) , statistics , test (biology) , mathematics , test theory , item response theory , sample size determination , test score , econometrics , psychometrics , standardized test , paleontology , discrete mathematics , rasch model , biology
Educational measurement specialists in undertaking test equating in applied settings have been plagued by the absence of a logically or mathematically compelling rationale for their test equating efforts. Classical test theory and other test theories based on the assumption of identically distributed true scores are tautological in terms of test equating. The present study examined (by means of a Monte Carlo procedure) the effects of four parameters on the accuracy of test equating under a relaxed definition of test form equivalence. The four parameters studied were sample size, test form length, test form reliability, and the correlation between the true scores of the test forms to be equated. Significant interactions involving sample size and the other parameters indicated that smaller samples of observations yielded disproportionately larger errors in test equating for fixed values of the test form parameters. In terms of main effects, sample size emerged as most important in controlling equating error. Taken together, the results suggest that when test equating is carried out on larger samples of observations, errors of equating will tend to be relatively small even though the test forms are not strictly parallel. For arbitrarily small samples, however, errors of equating will tend to be larger regardless of how equivalent the test forms are.