Denoting the base-free measure of change

Bond criticized the base-free measure of change proposed by Tucker, Damarin, and Messick by pointing to an incorrect derivation which is here viewed instead as a correct derivation entailing an inadequately specified tacit assumption. Bond's revision leads to estimates of the correlation between initial position and change which are negatively biased by correlated errors, whereas the original approach, with the tacit assumption properly denoted, leads to unbiased values.     

On the base-free measure of change proposed by Tucker,Damarin and Messick

Tucker, Damarin and Messick proposed a base-free measure of change which involves the computation of residual scores that are uncorrelated with true scores on the pretest. The present note discusses this change measure and demonstrates that, because of an incorrect derivation by the authors, properties they attribute to (the coefficient for the regression of true scores from the second testing on true scores from the first testing) are, in fact, properties ofb, the ordinary regression coefficient. A correct derivation of the initial position—change correlation in terms of is obtained, and Tucker et al.'s discussion of the law of initial values is reconsidered.The preparation of this paper was supported by the Learning Research and Development Center supported in part as a research and development center by funds from the National Institute of Education.     

A base-free measure of change

A model for the measurement of the discrepancy between two scores is presented and discussed as a paradigm for the study of growth or experimentally produced change. The model assumes two tests or measures differing in complexity, and it analyzes the true difference between the test scores into a component that is entirely dependent on the first or base-line test and a second component that is entirely independent of it. Equations for estimating both components are given and these are compared with other measurement efforts with similar goals.     

Kelley's formula as a basis for the assessment of reliable change

In the literature on the measurement of change,reliable change is usually determined by means of a confidence interval around an observed value of a statistic that estimates thetrue change. In recent literature on the efficacy of psychotherapies, attention has been particularly directed at the improvement of the estimation of the true change. Reliable Change Indices, incorporating thereliability-weighted measure of individual change, also known as Kelley's formula, have been proposed. According to current practice, these indices are defined as the ratio of such an estimator and an intuitively appealing criterion and then regarded as standard normally distributed statistics. However, because the authors fail to adopt an adequate standard error of the estimator, the statistical properties of their indices are unclear. In this article, it is shown that this can lead to paradoxical conclusions. The adjusted standard error is derived.     

A note on Tryon's measure of reliability

Two alternative formulas, based upon the analysis of variance, are given for Tryon's general form for the reliability coefficient.     

The relative error magnitude in three measures of change

Formulas for the standard error of measurement of three measures of change—simple difference scores, residualized difference scores, and the measure introduced by Tucker, Damarin, and Messick—are derived. Equating these formulas by pairs yields additional explicit formulas which provide a practical guide for determining the relative error of the three measures in any pretest-posttest design. The functional relationship between the standard error of measurement and the correlation between pretest and posttest observed scores remains essentially the same for each of the three measures despite variations in other test parameters (reliability coefficients, standard deviations), even when pretest and posttest errors of measurement are correlated.     

A further note on freeman's measure of association

This note extends and elaborates Hubert's attempt to provide an interpretation of Freeman's measure of association,. The measure is used in a a contingency table when observations are ordered on one variable and unordered on the other. No attempt is made explore the distribution of.     

On the identification of clinically significant client changes: Reinterpretation of Jacobson's cut scores

Cut points or cut scores play a central role in Jacobson's popular method of identifying clinically significant changes in psychotherapy. When pre- and posttherapy scores of a client are on different sides of one of these cut scores, the change is considered clinically significant, provided that it is also reliable (i.e., not due to measurement errors). This article critically examines the meanings and implications of these cut scores. Contrary to popular beliefs, they are generallynot the test scores for which the probability of belonging to the Functional population is equal to the probability of belonging to the Dysfunctional population. When the Functional population distribution is above that of the Dysfunctional population, persons scoring above these cut scores can, in fact, have much greater probabilities of belonging to the Dysfunctional than to the Functional population. Goals of Jacobson's method can be attained only with Bayesian methods. Bayesian modifications of Jacobson's cut scores are proposed, although their use is limited by the availability of relevant base rates. Bayesian methods (a) can provide information about the probability that an individual belongs to each population, given his (her) score, and (b) are expected to yield total misdiagnosis rates that are many times lower than those of Jacobson's method. Users of Jacobson's method are cautioned against interpreting ratios of likelihoods as if they were ratios of posterior probabilities.     

A note on moran's measure of multiple rank correlation

A measure of multiple rank correlation,T _y.12 ², is proposed for the situation with no tied observations in the variables. The measure is a weighted average of two squared Kendall taus. It is shown thatT _y.12 ² is equivalent to a statistic previously proposed by Moran and thus a new interpretation is given to Moran's statistic.The author wishes to thank Nancy Anderson, Willard Larkin, and Kent Norman for their helpful comments.     

A still further note on freeman's measure of association

This article demonstrates that Freeman's theta, a measure of association between a nominal variable and an ordinal variable, has a sampling distribution identical with the sampling distribution of Mann-Whitney'sU.     

Classical test theory based and factor analytic structural models for analyzing change: A note on differences and similarities

This note is concerned with differences and similarities between structural models for analyzing change, which are conceptualized within two different modelling traditions: the one based on the classical test theory, and that within the factor-analytic approach. It is shown that these two possibilities lead to models for studying change, which are indistinguishable when using for data analytic purposes structural modeling programs, such as LISREL, EQS, COSAN, LISCOMP, RAMONA, EzPATH, SAS PROC CALIS. The reason for this data-analytic equivalence of the two conceptually different types of models is the confounding of their differences in the corresponding implied covariance matrix structures.     

Detection of a change in photorealism1

The perceived degree of photorealism is interpreted as reflecting the artificialness or naturalness of images. Natural images (real‐scene photographs) are images with high degrees of naturalness, while artificial images (e.g., paintings) are images with low degrees of naturalness. Alternatively, natural images are images with low degrees of artificialness, while artificial images are images with high degrees of artificialness. We attempted to disambiguate these two interpretations of the perception of photorealism by using a change‐blindness paradigm. Participants observed an image sequence showing a gradual transformation from a natural image to an artificial image or vice versa, and reported changes they noticed. More participants reported noticing changes in photorealism for the natural‐to‐artificial transformations than for the opposite transformations. This asymmetry indicates that disappearing naturalness was detected more readily than emerging naturalness, or alternatively, emerging artificialness was detected more readily than disappearing artificialness. The results for the control conditions showed that the emergence of visual information was detected more readily than the disappearance. These results suggest that the perception of photorealism should be considered as the perception of artificialness.     

A note on latent trait theory and Bowker's test

Bowker's test for marginal equality in contingency tables provides a familiar chi-square test to determine whether the marginal distributions are the same across two or more factors or occasions. In this note it is shown how latent trait theory provides a theoretical framework for the development and application of this test.The research reported here was supported by a grant to the senior author from the National Institute on Aging (AG03164).     

A longitudinal study of the determinants and outcomes of career change

The present longitudinal field study investigated the antecedents and consequences of an actual career change. The framework for this study was Rhodes and Doering's (1983) model of career change. We examined the effect of individual and organisational characteristics on career change behaviour. The individual characteristics were: traits (Openness to Experience, Extraversion, Conscientiousness and general self-efficacy), demographic factors (age, gender, marital status, and children), human capital (education level and occupational tenure), job satisfaction, job search activity and intentions to leave; and organisational factors (job security and salary). The findings showed that a range of individual characteristics were associated with career change including, Openness to Experience, Extraversion, gender, age, educational level, and occupation tenure. However, job security was the only organisational factor related to career change. One year after career change, individuals reported higher job satisfaction, improved job security and a reduction in the number of hours worked.     

A note on Freeman's measure of association for relating an ordered to an unordered factor

Within the context of a contingency table, this note describes the relationship between Freeman's measure of association and the asymmetric association measures developed by Somers. The coefficient is appropriate for a contingency table in which the levels of one factor are ordered and the levels of the other factor are unordered; the indices defined by Somers are usually used when the levels of both factors are ordered and one is assumed to be the independent factor.     

Folkbiology meets microbiology: a study of conceptual and behavioral change

Health education can offer a valuable window onto conceptual and behavioral change. In Study 1, we mapped out 3rd-grade Chinese children’s beliefs about causes of colds and flu and ways they can be prevented. We also explored older adults’ beliefs as a possible source of the children’s ideas. In Study 2, we gave 3rd- and 4th-grade Chinese children either a conventional cold/flu education program or an experimental “Think Biology” program that focused on a biological causal mechanism for cold/flu transmission. The “Think Biology” program led children to reason about cold/flu causation and prevention more scientifically than the conventional program, and their reasoning abilities dovetailed with their mastery of the causal mechanism. Study 3, a modified replication of Study 2, found useful behavioral change as well as conceptual change among children who received the “Think Biology” program and documented coherence among knowledge enrichment, conceptual change, and behavioral change.     

The structure of paradigm change

I propose a concise picture of the core structure of paradigm change. It consists of the three basic steps which, I suggest, are common to all forms of paradigm change, individual as well as collective and in every conceptual domain. These steps are formularized so as to stimulate more precise theorizing about, and comparisons between various alleged forms of paradigm change. I explain the idea and give evidence for it using examples from the fields of cognitive psychology, moral psychology, and the history of science.     

The validity of the PTSD checklist as a measure of symptomatic change in combat-related PTSD

Little research to date has examined the ability of self-report measures to assess changes in symptom severity and diagnostic status as a function of treatment. This study investigated the validity of the posttraumatic stress disorder (PTSD) checklist (PCL) as a measure of symptomatic change following programmatic treatment. A sample of 97 Vietnam veterans with combat-related PTSD was assessed using the clinician-administered PTSD scale (CAPS) and the PCL prior to, and 9 months following, participation in a PTSD treatment program. Using the CAPS as the "gold standard" measure of PTSD symptomatology, the PCL demonstrated high diagnostic accuracy pre- and posttreatment. However, significant variations in accuracy were evident in the ability of the PCL to determine the presence and severity of individual symptoms at each time point. In addition, as symptoms improved from pre- to posttreatment, and approached the threshold criteria, the PCL demonstrated reductions in diagnostic accuracy. As a measure of overall symptomatic change, the PCL underrated improvement in comparison to the CAPS. The results supported the use of an overall cut-off score of 50 on the PCL for a diagnosis, and an item score of 3 for symptom criterion, in this population.