Hierarchical diffusion models for two-choice response times.

Two-choice response times are a common type of data, and much research has been devoted to the development of process models for such data. However, the practical application of these models is notoriously complicated, and flexible methods are largely nonexistent. We combine a popular model for choice response times—the Wiener diffusion process—with techniques from psychometrics in order to construct a hierarchical diffusion model. Chief among these techniques is the application of random effects, with which we allow for unexplained variability among participants, items, or other experimental units. These techniques lead to a modeling framework that is highly flexible and easy to work with. Among the many novel models this statistical framework provides are a multilevel diffusion model, regression diffusion models, and a large family of explanatory diffusion models. We provide examples and the necessary computer code. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Introduction to functional data analysis.

Psychologists and behavioural scientists are increasingly collecting data that are drawn from continuous underlying processes. We describe a set of quantitative methods, Functional Data Analysis (FDA), which can answer a number of questions that traditional statistical approaches cannot. These methods are applicable for analyzing many datasets that are common in experimental psychology, including time series data, repeated measures, and data distributed over time or space as in neuroimaging experiments. The primary advantage of FDA is that it allows the researcher to ask questions about when in a time series differences may exist between two or more sets of observations. We discuss functional correlations, principal components, the derivatives of functional curves, and analysis of variances models. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Levels of aggregation and the generalized matching law.

Concurrent operant behavior is often described using molar response tendencies measured over many sessions. In contrast, other models relate the allocation of behavior to momentary or molecular processes that operate over shorter periods. In this article, a formal model of the statistical properties of molecular behavioral matching is developed. Molar matching is the result when many individual bouts of responding are aggregated. However, behavioral allocation at the molecular level will differ from the molar result. The model indicates that aggregation effects should be controlled in analyses of matching and that the comparison of molecular theories of concurrent operant behavior with molecular models of matching performance affords ideographic analyses of choice behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using Multilevel Models to Analyze Couple and Family Treatment Data: Basic and Advanced Issues.

Couple and family treatment data present particular challenges to statistical analyses. Partners and family members tend to be more similar to one another than to other individuals, which raises interesting possibilities in the data analysis but also causes significant problems with classical, statistical methods. The present article presents multilevel models (also called hierarchical linear models, mixed-effects models, or random coefficient models) as a flexible analytic approach to couple and family longitudinal data. The article reviews basic properties of multilevel models but focuses primarily on 3 important extensions: missing data, power and sample size, and alternative representations of couple data. Information is presented as a tutorial, with a Web appendix providing datasets with SPSS and R code to reproduce the examples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personal space: The conceptual and measurement implications of structural equation models.

Investigated the stop-distance procedure for measuring personal space, using maximum likelihood estimation of structural equation models. Three data sets previously described by the author (see PA, Vols 67:5708 and 68:1091) were examined. Results challenge the factor model underlying recent estimates of the reliability of the stop-distance procedure and convincingly demonstrate the reliability of stop-distance measurements. About 97% of the variance in observed distances arose from sources other than structural measurement error. About 8% of the variance in measured distances was due to sources that reflected unidentified causal determinants of spacing. The repeated failures of the factor model and the repeated successes of the simplex model require a fundamental shift in the conceptualization of personal space. The failure of the factor model implies that momentary spatial preferences should not be considered as merely reflecting a stable underlying preference or as a repeated and momentary construction based on stable situational features. Personal space should be considered as a dynamic process that is continually open to modification but that shows considerable stability due to the persistence of previously maintained distances. (French abstract) (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Appraisal-emotion relationships in daily life.

Using a daily process design, the present study examined relationships between momentary appraisals and emotional experience based on Smith and Lazarus' (1993) theory of emotions (1993). Nine times a day for 2 weeks, participants (N = 33, 23 women) recorded their momentary experience of 2 positive emotions (joy, love) and 4 negative emotions (anger, guilt, fear, sadness) and the core relational theme appraisal contents Smith and Lazarus hypothesized as corresponding to these emotions. A series of multilevel modeling analyses found that the hypothesized relationships between appraisal contents and these emotions were stronger than relationships between contents and other emotions, although appraisals were related to other emotions in many cases. Moreover, there were some individual differences in the strength of these relationships. These results suggest that there are no one-to-one relationships between appraisal contents and specific emotional experiences, and that specific emotions are associated with different appraisal contents, and that specific appraisals are associated with different emotions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multilevel daily process designs for consulting and clinical psychology: A preface for the perplexed.

The next 3 articles in this issue use multilevel statistical procedures to analyze data collected in daily process studies of (a) stress and coping, (b) binge eating, and (c) chronic pain experience. Important differences in the methods and procedures of these studies illustrate the many options available to investigators and data analysts. This article serves as a preface to help readers who are new to these studies' methodology appreciate their novel contributions to the literature in consulting and clinical psychology. Four frequently asked questions are addressed concerning the design of daily process studies, the distinctive meaning of a within-person finding, the possibility that self-monitoring studies are measurement reactive, and complexities in the use of multilevel statistical procedures for analyzing person-day data sets. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Momentary Mood and Coping Processes in TMD Pain.

Temporomandibular dysfunction (TMD) pain, like many chronic pain problems, appears to be multiply determined. Patients with TMD pain of at least 6 months duration (N = 30) were administered questionnaires measuring dispositional coping styles and appraisals to explore the dynamic interactions of the pain and coping process. Patients were then issued handheld computers that prompted them to record their momentary pain and coping processes 4 times per day for 7 days. Hierarchical linear regression models using both the dispositional and momentary predictors indicated that momentary pain was a function both of dispositional tendency to catastrophize and of momentary measures of catastrophization, self-efficacy, and mood states. Results were seen as supporting a situational model of intervention for chronic TMD pain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structural equation modeling of multitrait-multimethod data: Different models for different types of methods.

The question as to which structural equation model should be selected when multitrait-multimethod (MTMM) data are analyzed is of interest to many researchers. In the past, attempts to find a well-fitting model have often been data-driven and highly arbitrary. In the present article, the authors argue that the measurement design (type of methods used) should guide the choice of the statistical model to analyze the data. In this respect, the authors distinguish between (a) interchangeable methods, (b) structurally different methods, and (c) the combination of both kinds of methods. The authors present an appropriate model for each type of method. All models allow separating measurement error from trait influences and trait-specific method effects. With respect to interchangeable methods, a multilevel confirmatory factor model is presented. For structurally different methods, the correlated trait-correlated (method-1) model is recommended. Finally, the authors demonstrate how to appropriately analyze data from MTMM designs that simultaneously use interchangeable and structurally different methods. All models are applied to empirical data to illustrate their proper use. Some implications and guidelines for modeling MTMM data are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multilevel modeling and school psychology: A review and practical example.

The purpose of this article is to provide an overview of the state of multilevel modeling in the field of school psychology. The authors provide a systematic assessment of published research of multilevel modeling studies in 5 journals devoted to the research and practice of school psychology. In addition, a practical example from the nationally representative Early Childhood Longitudinal Study—Kindergarten Cohort (ECLS–K) is presented to help school psychologists become familiar with the basic terminology and procedures used in multilevel modeling studies. Implications for statistical reform and future research practices are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measuring people intensively.

An overview is provided of measures that are administered repeatedly in daily life. Variations of this methodology have been referred to as ecological momentary assessment, diary methods, daily process measures, and most broadly as intensive repeated measures in naturalistic settings (IRM-NS). Contrasts are drawn between IRM-NS methods on the basis of different sampling strategies, such as time-contingent recording, signal-contingent recording, and event-contingent recording. Common threats to the internal validity, construct validity, and external validity of IRM-NS measures are reviewed, along with ways to reduce these threats. The statistical analysis of IRM-NS data is considered, with a particular focus on the investigation of intraindividual variability. An extended example is provided of an IRM-NS measure, an event-contingent recording method for the assessment of interpersonal behaviour. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of affective instability in ecological momentary assessment: Indices using successive difference and group comparison via multilevel modeling.

Temporal instability of affect is a defining characteristic of psychological disorders such as borderline personality disorder (BPD) and mood cycling disorders. Ecological momentary assessment (EMA) enables researchers to directly assess such frequent and extreme fluctuations over time. The authors examined 4 operationalizations of such temporal instability: the within-person variance (WPV), the first-order autocorrelation, the mean square successive difference (MSSD), and the probability of acute change (PAC). It is argued that the MSSD and PAC measures are preferred indices of affective instability because they capture both variability and temporal dependency in a time series. Additionally, the performance of these 2 measures in capturing within- and between-day instability is discussed. To illustrate, the authors present EMA data from a study of negative mood in BPD and major depressive disorder patients. In this study, MSSD and PAC captured affective instability better than did WPV. Given that MSSD and PAC are individual difference measures, the authors propose that group differences on these indices be explored using generalized multilevel models. Versions of MSSD and PAC that adjust for randomly elapsed time interval between assessments are also presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Introduction to the Special Section on Applied Longitudinal Methods in Aging Research.

This article introduces articles that appear in the special section on applied longitudinal methods in aging research. These articles apply quantitative statistical techniques such as multilevel modeling and structural equation models to the analysis of longitudinal data. They exemplify how applications of these techniques can advance scientific research on the effects of aging on psychological constructs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Award for Distinguished Scientific Early Career Contributions to Psychology: Robert E. Ployhart.

Robert E. Ployhart, recipient of the Award for Distinguished Scientific Early Career Contributions to Psychology, is cited for innovative work in examining reactions to staffing practices and efforts to enhance the acceptability of recruitment and staffing practices; for exemplary use of applied statistical models in examining multilevel effects and longitudinal hypotheses; and for leadership in promoting the use of multilevel models in selection research and in providing informative examples of such efforts. Ployhart’s conceptual models of the manner in which individual differences might be aggregated and affect outcomes at different levels of analysis than are usually evaluated in validation research have been groundbreaking. In addition to the citation, a biography and selected bibliography of Ployhart's works are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Incorporating a mulitilevel perspective into occupational stress research: Theoretical, methodological, and practical implications.

In recent years, scholars in organizational behavior and public health have recognized the value of multilevel modeling. This article draws from both of these fields to illustrate the benefits of incorporating a multilevel perspective into the study of occupational stress. The authors identify key multilevel issues in occupational stress in terms of (a) individual-level analyses, (b) group-level analyses, and (c) cross-level analyses. They integrate the theoretical points with statistical models to help illustrate how one can test multilevel occupational stress propositions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessing Psychological Change in Adulthood: An Overview of Methodological Issues.

This article reviews the current status of methods available for the analysis of psychological change in adulthood and aging. Enormous progress has been made in designing statistical models that can capture key aspects of intraindividual change, as reflected in techniques such as latent growth curve models and multilevel (random-effects) models. However, the rapid evolution of statistical innovations may have obscured the critical importance of addressing rival explanations for statistical outcomes, such as cohort differences or practice effects that could influence estimates of age-related change. Choice of modeling technique and implementation of a specific modeling approach should be grounded in and reflect both the theoretical nature of the developmental phenomenon and the features of the sampling design that selected persons, variables, and contexts for empirical observation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Levels of analysis issues in group psychology: Using efficacy as an example of a multilevel model.

Levels of analysis issues have attracted a lot of attention in group psychology research. Despite assertions pertaining to the value of multilevel models, most researchers focus on either the individual within groups or the group as a whole, but seldom on both. A multilevel approach may be helpful to group psychologists. This article addresses levels of analysis issues that are an inherent part of group research, and a number of methods that can be used to analyze multilevel data are presented. The methods fall into 3 categories: (a) assessing the extent of agreement within a single group, (b) contrasting within-group and between-groups variance, and (c) conducting multiple-level analyses. Finally, recommendations are offered for future multilevel research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Confusion and interest: The role of knowledge emotions in aesthetic experience.

What makes something confusing? Confusion is a common response to challenging, abstract, and complex works, but it has received little attention in psychology. On the basis of appraisal theories of emotion, I suggest that confusion and interest have different positions in a 2-dimensional appraisal space: Interesting things stem from appraisals of high novelty and high comprehensibility, and confusing things stem from appraisals of high novelty and low comprehensibility. Two studies—a multilevel correlational study and an experiment that manipulated comprehensibility—found support for this appraisal model. Confusion and interest are thus close relatives in the family of knowledge emotions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)