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Journal of Experimental… | 16 |
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Zimmerman, Donald W. | 16 |
Williams, Richard H. | 4 |
Zumbo, Bruno D. | 2 |
Publication Type
Journal Articles | 15 |
Reports - Research | 7 |
Reports - Evaluative | 6 |
Opinion Papers | 3 |
Information Analyses | 1 |
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Peer reviewed
Zimmerman, Donald W. – Journal of Experimental Education, 1977
Derives formulas for the validity of predictor-criterion tests that hold for all test scores constructed according to the expected-value concept of true score. These more general formulas disclose some paradoxical properties of test validity under conditions where errors are correlated and have some implications for practical testing situations…
Descriptors: Correlation, Criterion Referenced Tests, Scoring Formulas, Tables (Data)
Peer reviewed
Zimmerman, Donald W. – Journal of Experimental Education, 1987
A program obtained random samples from known populations, some of which violated the homogeneity assumption. Student t tests and Mann-Whitney U Tests were performed on the sample value. Where the t test led to incorrect decisions, the use of Mann-Whitney U test in its place led to poorer results. (JAZ)
Descriptors: Computer Software, Error of Measurement, Monte Carlo Methods, Nonparametric Statistics
Peer reviewed
Zimmerman, Donald W. – Journal of Experimental Education, 1986
A computer program randomly sampled ordered pairs of scores from known populations that departed from bivariate normal form and calculated correlation coefficients from sample values. Hypotheses were tested (1) that population correlations are zero using the t statistic; and (2) that population correlations have non-zero values using the r to z…
Descriptors: Correlation, Hypothesis Testing, Sampling, Statistical Distributions
Peer reviewed
Williams, Richard H.; Zimmerman, Donald W. – Journal of Experimental Education, 1984
This paper provides a list of 10 salient features of the standard error of measurement, contrasting it to the reliability coefficient. It is concluded that the standard error of measurement should be regarded as a primary characteristic of a mental test. (Author/DWH)
Descriptors: Educational Testing, Error of Measurement, Evaluation Methods, Psychological Testing
Peer reviewed
Zimmerman, Donald W.; And Others – Journal of Experimental Education, 1984
Three types of test were compared: a completion test, a matching test, and a multiple-choice test. The completion test was more reliable than the matching test, and the matching test was more reliable than the multiple-choice test. (Author/BW)
Descriptors: Comparative Analysis, Error of Measurement, Higher Education, Mathematical Models
Peer reviewed
Williams, Richard H.; Zimmerman, Donald W. – Journal of Experimental Education, 1982
The reliability of simple difference scores is greater than, less than, or equal to that of residualized difference scores, depending on whether the correlation between pretest and posttest scores is greater than, less than, or equal to the ratio of the standard deviations of pretest and posttest scores. (Author)
Descriptors: Achievement Gains, Comparative Analysis, Correlation, Pretests Posttests
Peer reviewed
Williams, Richard H.; Zimmerman, Donald W. – Journal of Experimental Education, 1982
A mathematical link between test reliability and test validity is derived, taking into account the correlation between error scores on a test and error scores on a criterion measure. When this correlation is positive, the "paradoxical" nonmonotonic relation between test reliability and test validity occurs universally. (Author/BW)
Descriptors: Correlation, Error of Measurement, Mathematical Models, Test Reliability
Peer reviewed
Williams, Richard H.; Zimmerman, Donald W. – Journal of Experimental Education, 1980
It is suggested that error of measurement cannot be routinely incorporated into the "error term" in statistical tests, and that the reliability of test scores does not have the simple relationship to statistical inference that one might expect. (Author/GK)
Descriptors: Error of Measurement, Hypothesis Testing, Mathematical Formulas, Test Reliability
Peer reviewed
Zimmerman, Donald W.; And Others – Journal of Experimental Education, 1981
Reliability coefficients of linear combinations of observed scores have anomalous properties which have led to difficulties in the investigation of difference scores and gain scores in test theory. Discrepancies between classical results and correct results obtained from more general formulas, which allow for correlated errors, are examined…
Descriptors: Error of Measurement, Mathematical Formulas, Mathematical Models, Scores
Peer reviewed
Zimmerman, Donald W. – Journal of Experimental Education, 1996
A simulation study demonstrates that transformation of scores to ranks reduces variance heterogeneity when scores with unequal variances are combined and ranked as one set, but not enough to prevent distortion of the probabilities of Type I and Type II errors of statistical significance tests. (SLD)
Descriptors: Scores, Simulation, Transformations (Mathematics)
Peer reviewed
Zimmerman, Donald W. – Journal of Experimental Education, 1992
The power functions of Student t tests performed on initial scores, ordinary ranks, 3 kinds of modular ranks, and dichotomies were investigated for 1 normal and 3 nonnormal distributions using 2 samples of 26 simulated scores each. Advantages of extending the rank transformation concept are discussed. (SLD)
Descriptors: Computer Simulation, Nonparametric Statistics, Power (Statistics), Scores
Peer reviewed
Zimmerman, Donald W.; And Others – Journal of Experimental Education, 1992
D. W. Zimmerman argues that the interpretation by J. D. Gibbons and S. Chakraborti of recent simulation results and their recommendations are misleading and suggests use of an alternate test when homogeneity of variance and normality are violated. Gibbons and Chakraborti review their differences with Zimmerman's position. (SLD)
Descriptors: Computer Simulation, Research Methodology, Research Reports, Sample Size
Peer reviewed
Zimmerman, Donald W.; Zumbo, Bruno D. – Journal of Experimental Education, 1992
A modified "F" test is derived that includes a correction for nonindependence of between-groups and within-groups sample values in analysis of variance (ANOVA) designs. Computer simulations based on normal and nonnormal distributions illustrate the usefulness of the approach, which was more powerful than conventional within-subjects…
Descriptors: Analysis of Variance, Computer Simulation, Correlation, Mathematical Models
Peer reviewed
Zimmerman, Donald W.; Zumbo, Bruno D. – Journal of Experimental Education, 1993
Comparisons of the Wilcoxon test, Friedman test, and repeated-measures analysis of variance (ANOVA) on ranks in a computer simulation show that the Friedman test performs like the sign test whereas the ANOVA performs like the Wilcoxon test. Classification of these tests in introductory statistics textbooks should be revised. (SLD)
Descriptors: Analysis of Variance, Classification, Comparative Analysis, Computer Simulation
Peer reviewed
Zimmerman, Donald W. – Journal of Experimental Education, 1998
Uses computer simulation to study the effects on parametric and nonparametric statistical tests when assumptions of normality and homogeneity of variance are violated. Results reveal that nonparametric methods are not always acceptable substitutes for parametric methods in research studies when parametric assumptions are not satisfied. (SLD)
Descriptors: Computer Simulation, Nonparametric Statistics, Statistical Analysis
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