Browsing by Author "Hattie, John"

Now showing 1 - 7 of 7
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    An assessment of Stout's index of essential unidimensionality
    (1996) Hattie, John; Krakowski, Krzysztof; Rogers, H. Jane; Swaminathan, Hariharan
    A simulation study was conducted to evaluate the dependability of Stout’s T index of unidimensionality as used in his DIMTEST procedure. DIMTEST was found to dependably provide indications of unidimensionality, to be reasonably robust, and to allow for a practical demarcation between one and many dimensions. The procedure was not affected by the method used to identify the initial subset of unidimensional items. It was, however, found to be sensitive to whether the multidimensional data arose from a compensatory model or a partially compensatory model. DIMTEST failed when the matrix of tetrachoric correlations was non-Gramian and hence is not appropriate in such cases. Index terms: DIMTEST, essential unidimensionality, factor analysis, item response models, Stout’s test of unidimensionality, tetrachoric correlations, unidimensionality.
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    Communication apprehension: An assessment of Australian and United States data
    (1982) Hansford, B. C.; Hattie, John
    This study assessed the claims of unidimensionality for a measure of oral communication apprehension (Personal Report of Communication Apprehension). Eighteen independent samples, drawn from Australian and United States sources were used; and comparisons were made between the samples. Although similarities were found among the data sets with respect to internal consistency, frequency distributions, and item-total correlations, the claim of unidimensionality in the measure was rejected. It was also found that there were no overall differences between Australian and United States samples, no sex differences, and no age differences.
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    The constraining of parameters in restricted factor analysis
    (1988) Hattie, John; Fraser, Colin
    In restricted factor analysis each of the elements in the matrices (of factor loadings, factor correlations, and unique variances and covariances) can be fixed, free to be estimated, or constrained. In this paper it is argued that the common practice of constraining some parameters at 0 often is not psychologically meaningful. Alternative procedures for constraining parameters are presented and illustrated using data based on the Luria model. Index terms: Constrained parameters, Factor analysis, Factor correlations, Factor loadings, Factor uniqueness.
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    A four-stage factor analytic approach to studying behavioral domains
    (1981) Hattie, John
    Four stages in factor analyzing behavioral domains are outlined using a measure of mental well-being or self-actualization, the Personal Orientation Inventory (POI), as an example. The stages are (1) exploratory analysis to assess the number of factors ; (2) developing viable factor names that are based on theoretical arguments and ensuring that each factor consists of subscales that many researchers agree appropriately load on the factor; (3) assessing the goodness of fit using confirmatory factor analysis; and (4) cross-validating the hypothesis on new data sets. After such an analysis it is claimed that the latent structure of the POI relates to the factors Sensitivity to Self and to Others, Perception of Reality, Acceptance of Present Self, and Strongly Principled Yet Flexible When Confronting Others.
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    Methodology review: Assessing unidimensionality of tests and items
    (1985) Hattie, John
    Various methods for determining unidimensionality are reviewed and the rationale of these methods is assessed. Indices based on answer patterns, reliability, components and factor analysis, and latent traits are reviewed. It is shown that many of the indices lack a rationale, and that many are adjustments of a previous index to take into account some criticisms of it. After reviewing many indices, it is suggested that those based on the size of residuals after fitting a two- or three-parameter latent trait model may be the most useful to detect unidimensionality. An attempt is made to clarify the term unidimensional, and it is shown how it differs from other terms often used interchangeably such as reliability, internal consistency, and homogeneity. Reliability is defined as the ratio of true score variance to observed score variance. Internal consistency denotes a group of methods that are intended to estimate reliability, are based on the variances and the covariances of test items, and depend on only one administration of a test. Homogeneity seems to refer more specifically to the similarity of the item correlations, but the term is often used as a synonym for unidimensionality. The usefulness of the terms internal consistency and homogeneity is questioned. Unidimensionality is defined as the existence of one latent trait underlying the data.
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    A Monte Carlo investigation of several person and item fit statistics for item response models
    (1987) Rogers, H. Jane; Hattie, John
    This study investigated the behavior of several person and item fit statistics commonly used to test and obtain fit to the one-parameter item response model. Using simulated data for 500 persons and 15 items, the sensitivity of the total-t, mean-square residual, and between-t fit statistics to guessing, heterogeneity in discrimination parameters, and multidimensionality was examined. Additionally, 25 misfitting persons and a misfitting item were generated to test the power of the three fit statistics to detect deviations in a subset of observations. Neither the total-t nor the mean-square residual were able to detect deviation from any of the models fitted. Use of these statistics appears to be unwarranted. The between-t was a useful indicator of guessing and heterogeneity in discrimination parameters, but was unable to detect multidimensionality. These results show that use of person and item fit statistics to test and obtain overall fit to the one-parameter model can lead to acceptance of the model even when it is grossly inappropriate. Assessments of model fit based on this strategy are inadequate. Alternative methods must be sought.
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    Procedures for assessing the validities of tests using the "known-groups" method
    (1984) Hattie, John; Cooksey, Ray W.
    If a test is "valid," one criterion could be that test scores must discriminate across groups that are theoretically known to differ. A procedure is outlined to assess the discrimination across groups that uses only information from means. The method can be applied to many published tests, it provides information that relates to the construct validity of the test, and it presents a way to identify how a new sample can be related to previous studies.