Specifying Ability Growth Models Using a Multidimensional Item Response Model for Repeated Measures Categorical Ordinal Item Response Data

When categorical ordinal item response data are collected over multiple timepoints from a repeated measures design, an item response theory (IRT) modeling approach whose unit of analysis is an item response is suitable. This study proposes a few longitudinal IRT models and illustrates how a popular compensatory multidimensional IRT model can be utilized to formulate such longitudinal IRT models, which permits an investigation of ability growth at both individual and population levels. The equivalence of an existing multidimensional IRT model and those longitudinal IRT models is also elaborated so that one can make use of an existing multidimensional IRT model to implement the longitudinal IRT models.     

Leader‐driven distortion of probability and payoff information affects choices between risky prospects

Research indicating that decision makers often distort new information to favor nascent preferences has focused primarily on riskless choice rather than risky choice. In addition, the critical assumption that information distortion mediates the link between the initially preferred alternative and the final choice has not been tested in a compelling manner. In an experiment designed to fill these gaps, participants made six choices involving pairs of hypothetical three‐outcome monetary gambles. We manipulated initial preferences by varying the order in which gamble features were presented. Multilevel regressions indicated that participants distorted their evaluations of precise probabilities and payoffs in the direction of their emerging preferences and that they used their biased evaluations to update those preferences. As expected, information distortion mediated the effect of initial preferences on final choices and final preference strength. In a follow‐up experiment, we compared a standard measure of information distortion (based on comparisons to mean ratings in a no‐choice control task) to a more personalized measure (based on participants' own ratings in the control task) and found the mean‐based measure to be superior for the probability and payoff information in question. Other findings in Experiment 2 corroborated the results of Experiment 1. In both studies, the distortion of quantitative inputs in a simple task highlights the non‐normative circularity of the choice process. Copyright © 2010 John Wiley & Sons, Ltd.     

Visual field differences in visual word recognition can emerge purely from perceptual learning: evidence from modeling Chinese character pronunciation

In Chinese orthography, a dominant character structure exists in which a semantic radical appears on the left and a phonetic radical on the right (SP characters); a minority opposite arrangement also exists (PS characters). As the number of phonetic radical types is much greater than semantic radical types, in SP characters the information is skewed to the right, whereas in PS characters it is skewed to the left. Through training a computational model for SP and PS character recognition that takes into account of the locations in which the characters appear in the visual field during learning, but does not assume any fundamental hemispheric processing difference, we show that visual field differences can emerge as a consequence of the fundamental structural differences in information between SP and PS characters, as opposed to the fundamental processing differences between the two hemispheres. This modeling result is also consistent with behavioral naming performance. This work provides strong evidence that perceptual learning, i.e., the information structure of word stimuli to which the readers have long been exposed, is one of the factors that accounts for hemispheric asymmetry effects in visual word recognition.     

A comparison of two flash-card methods for improving sight-word reading

Flash cards have been shown to be useful for teaching sight-word reading. To date, the most effective flash-card instruction method is incremental rehearsal (IR). This method involves the instructor interspersing unknown stimulus items into the presentation of known stimulus items. In this study, we compared IR to a modified IR procedure-strategic incremental rehearsal (SIR)-to determine whether the effects of IR might be improved by incorporating variables likely to increase word acquisition. These included increased opportunities to respond to unknown stimuli, using learner responding as a basis for changing instructional items, and systematic prompting methods. An A-B-A-B design was used to compare the effects of IR and SIR for increasing sight-word reading with 4 elementary school students. Results indicated that students read more words correctly with SIR than with IR. In addition, similar patterns of responding were seen at a 2-week follow-up.     

Implementing continuous non-normal skewed distributions in latent growth mixture modeling: An assessment of specification errors and class enumeration

Abstract

Recent advances have allowed for modeling mixture components within latent growth modeling using robust, skewed mixture distributions rather than normal distributions. This feature adds flexibility in handling non-normality in longitudinal data, through manifest or latent variables, by directly modeling skewed or heavy-tailed latent classes rather than assuming a mixture of normal distributions. The aim of this study was to assess through simulation the potential under- or over-extraction of latent classes in a growth mixture model when underlying data follow either normal, skewed-normal, or skewed-t distributions. In order to assess this, we implement skewed-t, skewed-normal, and conventional normal (i.e., not skewed) forms of the growth mixture model. The skewed-t and skewed-normal versions of this model have only recently been implemented, and relatively little is known about their performance. Model comparison, fit, and classification of correctly specified and mis-specified models were assessed through various indices. Findings suggest that the accuracy of model comparison and fit measures are dependent on the type of (mis)specification, as well as the amount of class separation between the latent classes. A secondary simulation exposed computation and accuracy difficulties under some skewed modeling contexts. Implications of findings, recommendations for applied researchers, and future directions are discussed; a motivating example is presented using education data.     

Effect Partitioning in Cross-Sectionally Clustered Data Without Multilevel Models

Abstract

Effect partitioning is almost exclusively performed with multilevel models (MLMs) – so much so that some have considered the two to be synonymous. MLMs are able to provide estimates with desirable statistical properties when data come from a hierarchical structure; but the random effects included in MLMs are not always integral to the analysis. As a result, other methods with relaxed assumptions are viable options in many cases. Through empirical examples and simulations, we show how generalized estimating equations (GEEs) can be used to effectively partition effects without random effects. We show that more onerous steps of MLMs such as determining the number of random effects and the structure for their covariance can be bypassed with GEEs while still obtaining identical or near-identical results. Additionally, violations of distributional assumptions adversely affect estimates with MLMs but have no effect on GEEs because no such assumptions are made. This makes GEEs a flexible alternative to MLMs with minimal assumptions that may warrant consideration. Limitations of GEEs for partitioning effects are also discussed.     

Specifying the Interrelationship Between Exposure to Violence and Parental Monitoring for Younger Versus Older Adolescents: A Five Year Longitudinal Test

Five waves of longitudinal data collected from 349 African American youth living in extreme poverty were used to examine the interrelationship between exposure to violence and parenting during adolescence. Semi-parametric group based modeling was used to identify trajectories of parental monitoring and exposure to violence from T1 to T5. Results from these analyses revealed: (1) a trajectory of declining parental monitoring for 48% of youth; and (2) four distinct trajectories of exposure to violence. Multivariate findings were largely consistent with the ecological-transactional model of community violence. Youth with stable and/or increasing trajectories of exposure to violence were more likely than youth with stable-low exposure to violence to have declining parental monitoring, but additional analyses revealed a similar pattern of findings for younger adolescents (age 9–11 T1), but no evidence of linkages between trajectories of exposure to violence and parental monitoring for older adolescents (age 12–16 T1). The theoretical and policy implications of these findings as well as areas for future research are also discussed.     

Time frames and the distinction between affective and cognitive well-being

We examined whether the empirical differences between affective well-being (AWB) and cognitive well-being (CWB) might be due to (a) the use of different time frames in measures of AWB and CWB or (b) structural differences. In Study 1, a multitrait-multimethod (MTMM) analysis indicated that levels of different components are more similar but do not converge completely when the same time frame is used. In Study 2, we found that people are more likely to consider global life circumstances (as opposed to specific events and activities) when they evaluate their CWB, regardless of the specific time frame. In both studies, the time frame did not moderate the associations between AWB and CWB and important correlates (personality, life circumstances).     

Smoking mediates the effect of conscientiousness on mortality: The Veterans Affairs Normative Aging Study

This study examined the relationship between conscientiousness and mortality over 18 years and whether smoking behavior mediated this relationship. We utilized data from the Veterans Affairs Normative Aging Study on 1349 men who completed the Goldberg (1992) adjectival markers of the Big Five. Over the 18-year follow-up, 547 (41%) participants died. Through proportional hazards modeling in a structural equation modeling framework, we found that higher levels of conscientiousness significantly predicted longer life, and that this effect was mediated by current smoking status at baseline. Methodologically, we also demonstrate the effectiveness of using a structural equation modeling framework to evaluate mediation when using a censored outcome such as mortality.