Representation and working memory in early arithmetic

Working memory has been implicated in the early acquisition of arithmetic skill, but the relations among different components of working memory, performance on different types of arithmetic problems, and development have not been explored. Preschool and Grade 1 children completed measures of phonological, visual-spatial, and central executive working memory, as well as nonverbal and verbal arithmetic problems, some of which included irrelevant information. For preschool children, accuracy was higher on nonverbal problems than on verbal problems, and the best and only unique predictor of performance on the standard nonverbal problems was visual-spatial working memory. This finding is consistent with the view that most preschoolers use a mental model for arithmetic that requires visual-spatial working memory. For Grade 1 children, performance was equivalent on nonverbal and verbal problems, and phonological working memory was the best predictor of performance on standard verbal problems. For both age groups, problems with added irrelevant information were substantially more difficult than standard problems, and in some cases measures of the central executive predicted performance. Assessing performance on different components of working memory in conjunction with different types of arithmetic problems provided new insights into the developing relations between working memory and how children do arithmetic.     

The Meaning vs. The Medical Model in the Empirically Supported Treatment Program: A Consideration of The Empirical Evidence

A review of the debate on the Empirically Supported Treatment Program is presented. It is argued that underlying the specifics of the debate are fundamentally incompatible paradigms: a meaning vs. a medical model. The findings from two gold standard multi-site studies are reviewed to conclude that the control condition meets requirements for an empirically supported treatment. The empirical finding of the failure of clinical training to improve treatment outcomes is explained by the focus on rational factors in training. It is recommended that training of therapists focus on enhancing experiential capacity rather than mastery of manualized treatment approaches.     

On the existence and uniqueness of JML estimates for the partial credit model

A necessary and sufficient condition is given in this paper for the existence and uniqueness of the maximum likelihood (the so-called joint maximum likelihood) estimate of the parameters of the Partial Credit Model. This condition is stated in terms of a structural property of the pattern of the data matrix that can be easily verified on the basis of a simple iterative procedure. The result is proved by using an argument of Haberman (1977). The author wishes to thank the Editor and the anonymous reviewers for their comments that helped to substantially improve the final version of this paper. This research was supported in part by a MURST grant (ex 60%).     

Checking the Assumptions of Rasch's Model for Speed Tests

Two new tests for a model for the response times on pure speed tests by Rasch (1960) are proposed. The model is based on the assumption that the test response times are approximately gamma distributed, with known index parameters and unknown rate parameters. The rate parameters are decomposed in a subject ability parameter and a test difficulty parameter. By treating the ability as a gamma distributed random variable, maximum marginal likelihood (MML) estimators for the test difficulty parameters and the parameters of the ability distribution are easily derived. Also the model tests proposed here pertain to the framework of MML. Two tests or modification indices are proposed. The first one is focused on the assumption of local stochastic independence, the second one on the assumption of the test characteristic functions. The tests are based on Lagrange multiplier statistics, and can therefore be computed using the parameter estimates under the null model. Therefore, model violations for all items and pairs of items can be assessed as a by-product of one single estimation run. Power studies and applications to real data are included as numerical examples.     

Fitting Psychometric Models with Methods Based on Automatic Differentiation

Quantitative psychology is concerned with the development and application of mathematical models in the behavioral sciences. Over time, models have become more complex, a consequence of the increasing complexity of research designs and experimental data, which is also a consequence of the utility of mathematical models in the science. As models have become more elaborate, the problems of estimating them have become increasingly challenging. This paper gives an introduction to a computing tool called automatic differentiation that is useful in calculating derivatives needed to estimate a model. As its name implies, automatic differentiation works in a routine way to produce derivatives accurately and quickly. Because so many features of model development require derivatives, the method has considerable potential in psychometric work. This paper reviews several examples to demonstrate how the methodology can be applied. From the Presidential Address delivered at the 70th Annual Meeting of the Psychometric Society, Tilburg University, The Netherlands, July 5–8, 2005.     

Adolescent Psychopathy and the Big Five: Results from Two Samples

The present study examines the relation between psychopathy and the Big Five dimensions of personality in two samples of adolescents. Specifically, the study tests the hypothesis that the aspect of psychopathy representing selfishness, callousness, and interpersonal manipulation (Factor 1) is most strongly associated with low Agreeableness, whereas the aspect of psychopathy representing impulsivity, instability, and social deviance (Factor 2) is associated with low Agreeableness, low Conscientiousness, and high Neuroticism. Data from 13- and 16-year-old boys and their mothers from two samples of the Pittsburgh Youth Study are used to test these hypotheses. Results were consistent across age and rating source in supporting the initial hypotheses, providing support for the construct of juvenile psychopathy and the interpretation of psychopathy as a constellation of traits drawn from a general model of personality functioning.     

A Multitrait–Multisource Confirmatory Factor Analytic Approach to the Construct Validity of ADHD and ODD Rating Scales with Malaysian Children

Confirmatory factor analysis (CFA) was used to model a multitrait by multisource matrix to determine the convergent and discriminant validity of measures of attention-deficit hyperactivity disorder (ADHD)-inattention (IN), ADHD-hyperactivity/impulsivity (HI), and oppositional defiant disorder (ODD) in 917 Malaysian elementary school children. The three trait factors were ADHD-IN, ADHD-HI, and ODD. The two source factors were parents and teachers. Similar to earlier studies with Australian and Brazilian children, the parent and teacher measures failed to show convergent and discriminant validity with Malaysian children. The study outlines the implications of such strong source effects in ADHD-IN, ADHD-HI, and ODD measures for the use of such parent and teacher scales to study the symptom dimensions.     

Masculinity, Femininity, and the Bem Sex Role Inventory in Turkey

The aim of this study was to examine the masculinity and femininity scales of Bem Sex Role Inventory (BSRI) among Turkish university students. Five hundred thirty-six students (280 men and 256 women) volunteered to complete the short-form of the BSRI and answer demographic questions. In factor analyses, the original factor structure (Bem, 1981) was found both in the mens and womens data. Comparisons of the factor structures with target rotation (Procrustes rotation) and comparison indexes showed no difference between the factor structures found among men and women. The internal consistency of the masculinity and femininity scales was acceptable, and t-tests showed that women scored higher on the femininity scale, and men scored higher on the masculinity scale. There were significant differences between men and women only on two masculinity items, but significant differences were found in 8 (of 10) femininity items.     

Measurement Structure of the Turkish Translation of the Child Behavior Checklist Using Confirmatory Factor Analytic Approaches to Validation of Syndromal Constructs

The new correlated 8-factor measurement structure of the Child Behavior Checklist for ages 6-18 (CBCL/6-18; T. M. Achenbach & L. A. Rescorla, 2001) derived from an American sample was used as a benchmark to evaluate its generalizability to Turkish general population (N = 5,195) and clinical (N = 963) samples. Item-level confirmatory factor analysis (CFA) was used to evaluate the adequacy of the correlated 8-factor model across 3 sample conditions (general population, clinical, and combined sample whose Total Problems scores were above the Turkish national median). The results supported the generalizability of the overall measurement structure of the CBCL to the Turkish population.     

Child Maltreatment and Emergent Personality Organization: Perspectives from the Five-Factor Model

The Five-Factor Model was used to examine personality organization in 211 six-year-old children (135 maltreated and 76 nonmaltreated). Longitudinal assessments were conducted at ages 7, 8, and 9. Six-year-old maltreated children exhibited lower agreeableness, conscientiousness, and openness to experience and higher neuroticism than did nonmaltreated children. Maltreated children also were more frequently represented in less adaptive personality clusters than were their nonmaltreated counterparts. A particularly vulnerable profile occurred predominantly among maltreated children and was related to experiencing both abuse and neglect. Child maltreatment and personality clusters were related to individual differences perceived by peers. Longitudinal stability of the personality dimensions also was assessed. At age nine, evidence was found for maintenance of the organization of the personality clusters obtained at age six and for continuity of maltreated children's personality liabilities.