On this page all my publications are listed. There is also an "old-school" version is available in APA-style.

Improving Transparency and Replication in Bayesian Statistics: The WAMBS-Checklist

Bayesian statistical methods are slowly creeping into all fields of science and are becoming ever more popular in applied research. Although it is very attractive to use Bayesian statistics, our personal experience has led us to believe that naively applying Bayesian methods can be dangerous for at least 3 main reasons:

The GRoLTS-Checklist: Guidelines for Reporting on Latent Trajectory Studies

Estimating models within the mixture model framework, like latent growth mixture modeling (LGMM) or latent class growth analysis (LCGA), involves making various decisions throughout the estimation process. This has led to a wide variety in how results of latent trajectory analysis are reported.

Testing Small Variance Priors Using Prior-Posterior Predictive P-values

Muthen and Asparouhov (2012) propose to evaluate model fit in structural equation models based on approximate (using small variance priors) instead of exact equality of (combinations of) parameters to zero. This is an important development that adequately addresses Cohen’s (1994) “The earth is round (p < .05)”, which stresses that point null-hypotheses are so precise that small and irrelevant differences from the null-hypothesis may lead to their rejection.

Application and Evaluation of an Expert Judgment Elicitation Procedure for Correlations

The purpose of the current study was to apply and evaluate a procedure to elicit expert judgments about correlations, and to update this information with empirical data. The result is a face-to-face group elicitation procedure with as its central element a trial roulette question that elicits experts’ judgments expressed as distributions.

A Bildung-psychological investigation into student motives: McKinsey- or von Humboldt-oriented?

This study examined differential student motives among students from a social sciences bachelor’s degree, and whether this difference related to participating in educational programmes for broader intellectual formation (Bildung). Survey research was conducted among 432 Dutch students (79.5% female), ranging in age from 17 to 32 years (Mage = 21.12, SD = 2.08).

Child and adolescent internalizing and externalizing problems 12 months postburn: the potential role of preburn functioning, parental posttraumatic stress, and informant bias

Adjustment after pediatric burn injury may be a challenge for children as well as their parents. This prospective study examined associations of internalizing and externalizing problems in children and adolescents 12 months postburn with preburn functioning, and parental acute and chronic posttraumatic stress symptoms (PTSS) from different perspectives.

PTSD Symptom Trajectories in Disaster Volunteers: The Role of Self-Efficacy, Social Acknowledgement, and Tasks Carried Out

Millions of volunteers respond after disasters, with a 24% to 46% risk of developing posttraumatic stress disorder (PTSD). It is unclear which symptom trajectories develop and how they differ between core (volunteering before the disaster) and noncore volunteers (joining after the disaster) and which factors predict trajectories.

Direct Aggression and Generalized Anxiety in Adolescence: Heterogeneity in Development and Intra-Individual Change

Co-occurrence of aggression and anxiety might change during adolescence, or stay stable. We studied change and stability of four types of co-occurrence regarding direct aggression and anxiety in adolescence: an anxious and non-aggressive type, an aggressive and non-anxious type, a comorbid aggressive-anxious type and a no problems type.

Possible Solution to Publication Bias Through Bayesian Statistics

The present paper argues that an important cause of publication bias resides in traditional frequentist statistics forcing binary decisions. An alternative approach through Bayesian statistics provides various degrees of support for any hypothesis allowing balanced decisions and proper null hypothesis testing, which may prevent publication bias.

Effectiveness, Mediators, and Effect Predictors of Internet Interventions for Chronic Cancer-Related Fatigue

This paper describes the design and analysis plan that will be used to study 2 Internet interventions aimed at reducing severe fatigue in cancer survivors: a mobile ambulant activity feedback therapy supported through a weekly email by a physiotherapist and a weekly Web- and mindfulness-based cognitive therapy supported online by a psychologist.

Analyzing small data sets using Bayesian estimation: the case of posttraumatic stress symptoms following mechanical ventilation in burn survivors

The analysis of small data sets in longitudinal studies can lead to power issues and often suffers from biased parameter values. These issues can be solved by using Bayesian estimation in conjunction with informative prior distributions.

Social Influence Interpretation of Interpersonal Processes and Team Performance Over Time Using Bayesian Model Selection

The team behavior literature is ambiguous about the relations between members’ interpersonal processes—task debate and task conflict—and team performance. From a social influence perspective, we show why members’ interpersonal processes determine team performance over time in small groups.

Reducing bias due to systematic attrition in longitudinal studies: The benefits of multiple imputation

Most longitudinal studies are plagued by drop-out related to variables at earlier assessments (systematic attrition). Although systematic attrition is often analysed in longitudinal studies, surprisingly few researchers attempt to reduce biases due to systematic attrition, even though this is possible and nowadays technically easy.

From a PhD to What? The Importance of the education-employment transition: Lessons from the Netherlands

The number of PhD graduates is on the rise. With the exception of Poland, all of the OECD countries experienced an increase in PhD graduates in the past decade (OECD, 2013). The increase in PhD graduates attests to a growth in knowledge and innovation, a growth that can be advantageous for academia, government and industry alike.

Measuring Implementation of a School-Based Violence Prevention Program: Fidelity and Teachers’ Responsiveness as Predictors of Proximal Outcomes

When school-based prevention programs are put into practice, evaluation studies commonly only consider one indicator of program implementation. The present study investigates how two different aspects of program implementation – fidelity and participant responsiveness – jointly influence proximal outcomes of the school-based violence prevention program ViSC.

Analyzing indirect effects in cluster randomized trials. The effect of estimation method, number of groups and group sizes on accuracy and power

Cluster randomized trials assess the effect of an intervention that is carried out at the group or cluster level. Ajzen’s theory of planned behavior is often used to model the effect of the intervention as an indirect effect mediated in turn by attitude, norms and behavioral intention.

Costs and Benefits of Bullying in the Context of the Peer Group: A Three Wave Longitudinal Analysis

Whereas previous research has shown that bullying in youth is predictive of a range of negative outcomes later in life, the more proximal consequences of bullying in the context of the peer group at school are not as clear. The present three-wave longitudinal study followed children (N = 394; 53 % girls; Mage = 10.3 at Time 1) from late childhood into early adolescence.

The Satisfaction With Life Scale: Measurement invariance across immigrant groups

The current study examined measurement invariance of the Satisfaction With Life Scale (SWLS; Diener, Emmons, Larsen, & Griffin, 1985) across three immigrant groups, namely, immigrants from the Former Soviet Union (FSU) in Israel, Turkish-Bulgarians, and Turkish-Germans. The results demonstrate measurement invariance of the SWLS across groups.

Facing off with Scylla and Charybdis: a comparison of scalar, partial, and the novel possibility of approximate measurement invariance

Measurement invariance (MI) is a pre-requisite for comparing latent variable scores across groups. The current paper introduces the concept of approximate MI building on the work of Muthén and Asparouhov and their application of Bayesian Structural Equation Modeling (BSEM) in the software Mplus.

What Took Them So Long? Explaining PhD Delays among Doctoral Candidates

A delay in PhD completion, while likely undesirable for PhD candidates, can also be detrimental to universities if and when PhD delay leads to attrition/termination. Termination of the PhD trajectory can lead to individual stress, a loss of valuable time and resources invested in the candidate and can also mean a loss of competitive advantage.

Understanding ethnic differences in mental health service use for adolescents’ internalizing problems: the role of emotional problem identification

Although immigrant adolescents are at least at equal risk of developing internalizing problems as their non-immigrant peers, immigrant adolescents are less likely to use mental health care. The present study is the first to examine ethnic differences in problem identification to find explanations for this disparity in mental health service use.

Bayesian evaluation of informative hypotheses in SEM using Mplus: A black bear story

Half in jest we use a story about a black bear to illustrate that there are some discrepancies between the formal use of the p-value and the way it is often used in practice. We argue that more can be learned from data by evaluating informative hypotheses, than by testing the traditional null hypothesis.

Bayesian Evaluation of Inequality-Constrained Hypotheses in SEM Models using Mplus

Researchers in the behavioral and social sciences often have expectations that can be expressed in the form of inequality constraints among the parameters of a structural equation model resulting in an informative hypothesis. The questions they would like an answer to are “Is the hypothesis Correct” or “Is the hypothesis incorrect”?

A checklist for testing measurement invariance

The analysis of measurement invariance of latent constructs is important in research across groups, or across time. By establishing whether factor loadings, intercepts and residual variances are equivalent in a factor model that measures a latent concept, we can assure that comparisons that are made on the latent variable are valid across groups or time.

Friends and Family Interview: Measurement invariance across Belgium and Romania

The Friends and Family Interview (FFI; Steele & Steele, 2005 Steele, H. and Steele, M. 2005. The construct of coherence as an indicator of attachment security in middle childhood: The Friends and Family Interview, New York, NY: Guilford Press), a semi-structured interview assessing attachment representations, is used in the context of an international research project.

Posttraumatic Stress Symptoms After Exposure to Two Fire Disasters: Comparative study

This study investigated traumatic stress symptoms in severely burned survivors of two fire disasters and two comparison groups of patients with “non-disaster” burn injuries, as well as risk factors associated with acute and chronic stress symptoms. Patients were admitted to one out of eight burn centers in the Netherlands or Belgium.

The employment status of doctoral recipients: An exploratory study in the Netherlands

Studies of employment often focus on general labour market developments or the employment status of vulnerable groups concentrated at the lower end of the labour market. In contrast, the employment of highly educated individuals, in particular PhD recipients, has received less empirical attention.

The Effect of Offenders’ Sex on Reporting Crimes to the Police

This article examines the difference in victims’ reporting behavior regarding crimes committed by males and by females. The authors expect that victims of female offenders are less likely to report to the police than victims of male offenders because of differences in the victim–offender relationship as well as in the victim’s sex.

Family Cohesion and Romantic and Sexual Initiation: A Three Wave Longitudinal Study

Although the relation between family relationships and the timing of sexual debut has been the focus of many studies, research on mediating factors is scarce. This study examines whether low levels of family cohesion result in an earlier onset of romantic and sexual experiences, and whether the link between family cohesion and an early sexual debut is mediated by early romantic initiation.

Lifelong Learning as a goal – Do autonomy and self-regulation in school result in well prepared pupils?

Fostering lifelong learning (LLL) is a topic of high relevance for current educational policy. School lays the cornerstone for the key components of LLL, specifically persistent motivation to learn and self-regulated learning behavior. The present study investigated the impact of classroom instruction variables on concrete determinants for these LLL components.

A prior predictive loss function for the evaluation of inequality constrained hypotheses

In many types of statistical modeling, inequality constraints are imposed between the parameters of interest. As we will show in this paper, the DIC (i.e., posterior Deviance Information Criterium as proposed as a Bayesian model selection tool by Spiegelhalter, Best, Carlin, & Van Der Linde, 2002) fails when comparing inequality constrained hypotheses.

Impact of pediatric burn camps on participants’ self esteem and body image: An empirical study

Quantitative as well as qualitative measures was used. To study possible effects, a pretest–posttest comparison group design with a follow-up was employed. Self-report questionnaires were used to measure self esteem and body image in a burn camp group (n = 83, 8–18 years) and in a comparison group of children with burns who did not attend a burn camp during the course of the study (n = 90, 8–18 years).

Cytokine Production by Leukocytes of Military Personnel with Depressive Symptoms after Deployment to a Combat-Zone: A Prospective, Longitudinal Study

Major depressive disorder (MDD) is frequently diagnosed in military personnel returning from deployment. Literature suggests that MDD is associated with a pro-inflammatory state. To the best of our knowledge, no prospective, longitudinal studies on the association between development of depressive symptomatology and cytokine production by peripheral blood leukocytes have been published.

An introduction to Bayesian model selection for evaluating informative hypotheses

Most researchers have specific expectations concerning their research questions. These may be derived from theory, empirical evidence, or both. Yet despite these expectations, most investigators still use null hypothesis testing to evaluate their data, that is, when analysing their data they ignore the expectations they have.

Directly evaluating expectations or testing the null hypothesis? Null hypothesis testing versus Bayesian model selection

Researchers in psychology have specific expectations about their theories. These are called informative hypothesis because they contain information about reality. Note that these hypotheses are not necessarily the same as the traditional null and alternative hypothesis.

Testing informative hypotheses in SEM increases power: An illustration contrasting classical hypothesis testing with a parametric bootstrap approach

In the present paper, the application of a parametric bootstrap procedure, as described by van de Schoot, Hoijtink, and Deković (2010), will be applied to demonstrate that a direct test of an informative hypothesis offers more informative results compared to testing traditional null hypotheses against catch-all rivals.

Evaluating expectations about negative emotional states of aggressive boys using Bayesian model selection

Researchers often have expectations about the research outcomes in regard to inequality constraints between, e.g., group means. Consider the example of researchers who investigated the effects of inducing a negative emotional state in aggressive boys.

Prolonged Grief Disorder, depression, and posttraumatic stress-disorder are distinguishable syndromes

This study examined the distinctiveness of symptoms of Prolonged Grief Disorder (PGD), depression, and posttraumatic stress disorder (PTSD). We compared the fit of a one-factor model with the fit of four hierarchical models in which symptoms formed three distinct correlated higher-order dimensions, and PTSD-items were modeled in different ways.