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

Mother, father and child traumatic stress reactions after paediatric burn

The current study examined occurrence and within-family associations of traumatic stress reactions after child burn injury, while in the same model addressing the role of parents’ own symptoms in their reports of child symptoms.

Bayes with Informed Priors Based on Literature and Expert Elicitation

Bayesian Trajectory Analysis with Informed Priors Based on a Systematic Literature Search and Expert Elicitation in the field of Post Traumatic Stress.

Manipulating the alpha level cannot cure significance testing

We argue that depending on p-values to reject null hypotheses, including a recent call for changing the canonical alpha level for statistical significance from .05 to .005, is deleterious for the finding of new discoveries and the progress of cumulative science.

People management: developing and testing a measurement scale

In this study we conceptualize people management and develop a multidimensional scale to measure it from the perspectives of both employees and line managers.

Hoe zat het ook alweer? Het betrouwbaarheidsinterval in intelligentietests

Hoe wordt een betrouwbaarheidsinterval van IQ-tests ook al weer opgesteld? Een opfriscursus aan de hand van de WISC-III-NL.

Applying guidelines to construct informative priors in small sample research

The current paper demonstrates the usefulness of Bayesian estimation with small samples. In Bayesian estimation, prior information can be included …

Systematic search of Bayesian statistics in the field of psychotraumatology

Bayesian analyses are slowly creeping into many areas of science, including the field of psychotraumatology.

Effectiveness of Interventions for Chronic Cancer-Related Fatigue: An RCT

Effectiveness of Two Web-Based Interventions for Chronic Cancer-Related Fatigue Compared to an Active Control Condition: Results of the “Fitter na kanker” Randomized Controlled Trial.

Multilevel Analysis: Techniques and Applications

Applauded for its clarity, this accessible introduction helps readers apply multilevel techniques to their research. The book also includes advanced extensions, making it useful as both an introduction for students and as a reference for researchers.

Bayesian statistics in educational research: a look at the current state of affairs

A steady accumulation of knowledge requires approaches which allow researchers to consider results from comparable prior research. Bayesian statistics is especially relevant for establishing a cumulative scientific discipline …

Physical Behavior Profiles in Chronic Cancer-Related Fatigue

Increasing physical activity level is a generally effective intervention goal for patients who suffer from chronic cancer-related fatigue (CCRF). However, patients are unlikely to benefit equally from these interventions,

A General procedure for Testing Inequality Constrained Hypotheses in SEM

Researchers in the social and behavioral sciences often have clear expectations about the order and/or the sign of the parameters in their statistical model. For example, a researcher might expect that regression coefficient β1 is larger than β2 and β3.

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:

An Introduction to Bayesian Statistics in Health Psychology

Bayesian methods are increasing in prevalence in applied fields, and they have been shown in simulation research to improve the estimation accuracy of structural equation models, latent growth curve models, and hierarchical linear models.

A Systematic Review of Bayesian Papers in Psychology: The Last 25 Years

Although the statistical tools most often used by researchers in the field of psychology over the last 25 years are based on frequentist statistics, it is often claimed that the alternative Bayesian approach to statistics is gaining in popularity.

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.

Simulation Study Introducing the BRMSEA

Evaluating model fit in Bayesian confirmatory factor analysis with large samples: Simulation study introducing the BRMSEA

Parents’ posttraumatic stress after burns in their school-aged child: A prospective study

Objective: This prospective study examined the course and potential predictors of parents’ posttraumatic stress symptoms (PTSS) after burn injury in their child (Age 8 to 18 years). Method: One hundred eleven mothers and 91 fathers, representing 118 children, participated in the study.

Computing complexity for the Bayes Factor in inequality constrained hypotheses

The computation of complexity for the Bayes Factor is described in this tutorial.

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.

Wat zijn de regels van de wetenschap en liggen die voor altijd vast?

“Lang… lang geleden, in een dorp hier ver vandaan, stelden de eerste wetenschappers Vragen. Op een dag besloten zij dat Vragen stellen veel beter ging als ze zich terugtrokken uit het dorp en in een ivoren toren gingen werken. Daar konden zij in alle rust zoeken naar mogelijke antwoorden op de Vragen.

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.

Introducing the Fling – An Innovative Serious Game to Train Behavioral Control in Adolescents: Protocol of a Randomized Controlled Trial

Behavioral control weaknesses are a strong predictor of problematic behaviors in adolescents, such as heavy alcohol use. Heavy alcohol use at this young age can lead to health and school-related problems and is a severe societal problem.

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).

Eye movement desensitisation and reprocessing therapy v. stabilisation as usual for refugees: randomised controlled trial

Eye movement desensitisation and reprocessing (EMDR) therapy is a first-line treatment for adults with post-traumatic stress disorder (PTSD). Some clinicians argue that with refugees, directly targeting traumatic memories through EMDR may be harmful or ineffective.

Fostering pupils’ lifelong learning competencies in the classroom: evaluation of a training programme using a multivariate multilevel growth curve approach

Evidence-based interventions to promote lifelong learning are needed not only in continuing education but also in schools, which lay important cornerstones for lifelong learning.

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.

The relationship between tics, OC, ADHD and autism symptoms

Gilles de la Tourette’s syndrome (GTS) is a disorder in which obsessive-compulsive (OC), Attention Deficit Hyperactivity Disorder (ADHD) and autism symptoms occur in up to 60% of patients, suggesting shared etiology.

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.

The Stability of Problem Behavior Across the Preschool Years: An Empirical Approach in the General Population

This study examined the stability of internalizing and externalizing problems from age 1.5 to 6 years, while taking into account developmental changes in the presentation of problems. The study comprised a population-based cohort of 7,206 children (50.4 % boys).

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.

VI European Congress of Methodology

From July 23 to 25, 2014, the VI European Congress of Methodology was held in Utrecht, the Netherlands. The European Congress of Methodology is organized biennially under the supervision of the European Association of Methodology (EAM), a society established in 2004, which brings together a large number of researchers from all over the world.

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.

Measurement Invariance (book)

Multi-item surveys are frequently used to study scores on latent factors, like human values, attitudes and behavior. Such studies often include a comparison, between specific groups of individuals, either at one or multiple points in time.

How to handle missing data: A comparison of different approaches

Many researchers face the problem of missing data in longitudinal research. Especially, high risk samples are characterized by missing data which can complicate analyses and the interpretation of results.

Collinear Latent Variables in Multilevel Confirmatory Factor Analysis: A Comparison of Maximum Likelihood and Bayesian Estimation

Because variables may be correlated in the social and behavioral sciences, multicollinearity might be problematic. This study investigates the effect of collinearity manipulated in within and between levels of a two-level confirmatory factor analysis by Monte Carlo simulation.

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.

Individual and class room predictors of same-cultural friendship preferences in multicultural schools

This study was an investigation of individual and contextual predictors for same-cultural friendship preferences among non-immigrant (n = 125), Turkish (n = 196) and former Yugoslavian (n = 256) immigrant youths (Mage= 14.39 years) in 36 multicultural classes.

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.

Latent trajectory studies: the basics, how to interpret the results, and what to report

In statistics, tools have been developed to estimate individual change over time. Also, the existence of latent trajectories, where individuals are captured by trajectories that are unobserved (latent), can be evaluated (Muthén & Muthén, 2000).

Latent Growth Mixture Models to estimate PTSD trajectories

Statistical models to estimate individual change over time and to investigate the existence of latent trajectories, where individuals belong to trajectories that are unobserved (latent), are becoming ever more popular.

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.

Personality and the Prediction of High-Risk Trajectories of Alcohol Use During Adolescence

Early onset of alcohol use and persistent use of alcohol during adolescence have been associated with later problem behavior, such as heavy drinking and the use of other substances.

Constrained statistical inference: sample-size tables for ANOVA and regression

Researchers in the social and behavioral sciences often have clear expectations about the order/direction of the parameters in their statistical model. For example, a researcher might expect that regression coefficient β1 is larger than β2 and β3.

Experience of traumatic events disrupts measurement invariance of a posttraumatic stress scale

Studies that include multiple assessments of a particular instrument within the same population are based on the presumption that this instrument measures the same construct over time. But what if the meaning of the construct changes over time due to one’s experiences?

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.

The relationship between behavioural problems in preschool children and parental distress after a paediatric burn event

This study examines mother- and father-rated emotional and behaviour problems in and worries about 0- to 5-year-old children at 3 and 12 months after a burn event and the relation with parental distress.

The effectiveness of a proactive coping intervention targeting self-management in diabetes patients

The study’s aim was to investigate psychological, behavioral and medical long-term outcomes of an existing self-management intervention targeting the development of proactive coping skills (e.g. goal setting and identifying barriers) in type 2 diabetes patients.

Promotion of students’ mastery goal orientations: does TARGET work?

Achievement goal orientations are important for students’ ongoing motivation. Students with a mastery goal orientation show the most advantageous achievement and motivational patterns. Much research has been conducted to identify classroom structures which promote students’ mastery goal orientation.

Guilt in Bereavement: The Role of Self-Blame and Regret in Coping with Loss

Despite the apparent centrality of guilt in complicating reactions following bereavement, scientific investigation has been limited. Establishing the impact of specific components associated with guilt could enhance understanding.

A Gentle Introduction to Bayesian Analysis: Applications to Developmental Research

Bayesian statistical methods are becoming ever more popular in applied and fundamental research. In this study a gentle introduction to Bayesian analysis is provided. It is shown under what circumstances it is attractive to use Bayesian estimation, and how to interpret properly the results.

Anger: Cause or Consequence of Posttraumatic Stress? A Prospective Study of Dutch Soldiers

Many studies have shown that individuals with posttraumatic stress disorder (PTSD) experience more anger over time and across situations (i.e., trait anger) than trauma-exposed individuals without PTSD. There is a lack of prospective research, however, that considers anger levels before trauma exposure.

Bayesian analyses: where to start and what to report

Most researchers in the social and behavioral sciences will probably have heard of Bayesian statistics in which probability is defined differently compared to classical statistics (probability as the long-run frequency versus probability as the subjective experience of uncertainty).

Measurement invariance of the Illness Invalidation Inventory

The Illness Invalidation Inventory (3*I) assesses patients’ perception of responses of others that are perceived as denying, lecturing, not supporting and not acknowledging the condition of the patient. It includes two factors: ‘discounting’ and ‘lack of understanding’.

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.

Using the Youth Self-Report internalizing syndrome scales among immigrant adolescents

Although the Youth Self-Report (YSR) has been used in many studies throughout the world, little is known about the equivalence of the factor structure of this instrument for immigrant adolescents.

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.

Automatic Processes and the Drinking Behavior in Early Adolescence: A Prospective Study

This study examined the bi-directional prospective link between automatic alcohol-approach tendencies and alcohol use in a group of young adolescents (mean age = 13.6 years). The adolescents in the present study were assumed to be at-risk of early alcohol use and later problem drinking.

Internet-Based Early Intervention to Prevent Posttraumatic Stress Disorder in Injury Patients: Randomized Controlled Trial

Posttraumatic stress disorder (PTSD) develops in 10-20% of injury patients. We developed a novel, self-guided Internet-based intervention (called Trauma TIPS) based on techniques from cognitive behavioral therapy (CBT) to prevent the onset of PTSD symptoms.

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.

The Burn Specific Health Scale-Brief: Measurement invariant across European countries

The Burn Specific Health Scale Brief (BSHS-B), which is the only multidimensional measure to evaluate burn-specific aspects of health status, has previously been validated in several languages across the world. However, the stability of the underlying construct was not cross-culturally evaluated.

Developmental trajectories of bullying and social dominance in youth

Bullying is increasingly conceptualized as strategic behavior motivated by a desire to gain social dominance in the peer group. Cross-sectional research has shown that relative to their peers bullies are higher in social dominance as indexed by resource control, and are often perceived as powerful and “cool.”

The effect of classroom structure on verbal and physical aggression among peers: A short-term longitudinal study

Teachers promote student learning and well-being in school by establishing a supportive classroom structure. The term classroom structure refers to how teachers design tasks, maintain authority, and evaluate student achievement.

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.

“Is the Hypothesis Correct” or “Is it Not”: Bayesian Evaluation of One Informative Hypothesis for ANOVA

Researchers in the behavioral and social sciences often have one informative hypothesis with respect to the state of affairs in the population from which they sampled their data. The question they would like an answer to is “Is the Hypothesis Correct” or “Is it Not.”

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”?

Mobiliteitsonderzoek Vernieuwingsimpuls-laureaten

In 2011 besloot NWO onderzoek te laten doen naar de wetenschappers die een subsidie ontvingen in het kader van de zogenoemde VernieuwingsImpuls (VI). Het gaat daarbij om drie typen subsidies die NWO als volgt omschrijft:

Do parents think it takes a village? Parents’ attitudes towards nonparental adults’ involvement in the upbringing and nurture of children

The current study explored parents’ attitudes towards nonparental adults’ involvement in childrearing practices. Parents’ attitudes were operationalized in their willingness to share parenting responsibility and interest to participate in parenting activities.

Meaning-in-life orientations and values in youth: Cross-cultural comparison

Search for purposes in life and the meaning of life is one of the developmental tasks in youth. The Meaning-in-Life Orientations test (MOL) is often used to assess purposes in life and meaningfulness of life and is often used to compare individuals and groups.

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.

The Structure of Peritraumatic Dissociation: A Cross Validation in Clinical and Nonclinical Samples

Empirical data have challenged the unidimensionality of the Peritraumatic Dissociative Experiences Questionnaire (PDEQ), a widely used measure for peritraumatic dissociation. The aim of this study was to assess the factor structure of the PDEQ in 3 trauma-exposed samples:

Bullying and Victimization in Ethnically Diverse Schools

Growing up in a multicultural society is becoming increasingly common for many children and youth in countries all over the world. Young people from different parts of the world meet together in schools spending a big amount of time with each other.

Identity Statuses as Developmental Trajectories. A Five-Wave Longitudinal Study in Early-to-Middle and Middle-to-Late Adolescents

This study tested whether Marcia’s original identity statuses of achievement, moratorium, early closure (a new label for foreclosure), and diffusion, can be considered identity status trajectories.

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.

Who are the Job Seekers? Unemployment among Doctoral Recipients

Despite increased attention for doctoral education in recent years, one particular phenomenon has received little attention—the unemployment of doctoral candidates following graduation.

Automatic processes in at-risk adolescents: the role of alcohol-approach tendencies and response inhibition in drinking behavior

This study examined the association between automatic processes and drinking behavior in relation to individual differences in response inhibition in young adolescents who had just started drinking.

One Size Does Not Fit All: proposal for a prior-adapted BIC

This paper presents a refinement of the Bayesian Information Criterion (BIC). While the original BIC selects models on the basis of complexity and fit, the so-called prior-adapted BIC allows us to choose among statistical models that differ on three scores: fit, complexity, and model size.

How few countries will do? Comparative survey analysis from a Bayesian perspective

Meuleman and Billiet (2009) have carried out a simulation study aimed at the question how many countries are needed for accurate multilevel SEM estimation in comparative studies. The authors concluded that a sample of 50 to 100 countries is needed for accurate estimation.

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.

Do Delinquent Young Adults have a High or a Low Level of Self-concept?

This study explored the levels of self-concept of delinquent young adults (n = 873). This question is of theoretical and practical importance, as therapeutic programs addressing the self-concept must be based on clear evidence.

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.

Measurement invariance of the Emotion Regulation Questionnaire (ERQ). A cross-national validity study

The goal of this research was to examine the measurement invariance of the Emotion Regulation Questionnaire (ERQ; Gross & John, 2003) across two European nations. Participants were Italian and German undergraduate students.

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.

Health-related quality of life after burns: A prospective multicenter cohort study with 18 months follow-up

Health-related quality of life (HRQOL) is an important parameter after medical treatments. Knowledge of (predictors of) diminished quality of life can help improve medical outcome.

Illustrating Bayesian evaluation of informative hypotheses for regression models

In the present article we illustrate a Bayesian method of evaluating informative hypotheses for regression models. Our main aim is to make this method accessible to psychological researchers without a mathematical or Bayesian background.

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.

PhD monitor 2011: PhD candidates from Utrecht University speak

Het oordeel van promovendi van de Universiteit Utrecht over opleiding, begeleiding en onderzoeksfaciliteiten.

Islamic and homosexual in the Netherlands – a double mental burden?

According to the Minority Stress Model, immigrants have an increased risk of mental health problems compared with the general population. Homosexual feelings can form an additional minority stress factor next to ethnic minority status, given the social disapproval of homosexuality within non-Western cultures,

The associations of humorous coping styles, affective states, job demands and job control with the frequency of upper respiratory tract infection

There is some evidence that job demands and job resources such as job control and humorous coping may contribute to the risk of upper respiratory tract infections (URTI).

The fate of PhD projects: Efficiency of social sciences subsidies

Eenderde van het Nederlandse promotieonderzoek wordt gefinancierd vanuit NWO. Het rendement hiervan is tot nu echter niet bekend. Rens van de Schoot, Hans Sonneveld en Ditte Lockhorst onderzochten de afloop van promotieprojecten bij de gedrags- en maatschappijwetenschappen.

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.

Moving beyond traditional null hypothesis testing: evaluating expectations directly

This mini-review illustrates that testing the traditional null hypothesis is not always the appropriate strategy. Half in jest, we discuss Aristotle’s scientific investigations into the shape of the earth in the context of evaluating the traditional null hypothesis.

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.

Can at-risk young adolescents be popular and anti-social? Sociometric status groups, anti-social behavior, gender and ethnic background

This study aimed to extend the understanding of anti-social behaviour and its association with popularity and sociometric status in a sample of at-risk adolescents from diverse ethnic backgrounds (n = 1491, average age 14.7 years).

Informative hypotheses: How to move beyond classical null hypothesis testing

Almost all researchers in psychology have specific expectations about their theories in the form of hypothesized order constraints between statistical parameters. For example: the mean of group 1 is larger than the mean of group 2 which in turn is larger than the mean of group 3.

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.

On the Progression and Stability of Adolescent Identity Formation. A Five-Wave Longitudinal Study in Early-to-Middle and Middle-to-Late Adolescence

This study examined identity development in a 5-wave study of 923 early-to-middle and 390 middle-to-late adolescents thereby covering the ages of 12–20.

Testing inequality constrained hypotheses in SEM Models

Researchers often have expectations that can be expressed in the form of inequality constraints among the parameters of a structural equation model. It is currently not possible to test these so-called informative hypotheses in structural equation modeling software.

Ph.D. Trajectories and Labour Market Mobility. A survey of recent doctoral recipients at four universities in the Netherlands

The results of a survey of recent doctoral recipients at four universities in The Netherlands.

Bayesian model selection of informative hypotheses for repeated measurements

When analyzing repeated measurements data, researchers often have expectations about the relations between the measurement means. The expectations can often be formalized using equality and inequality constraints between (i) the measurement means over time, (ii) the measurement means between groups,