How to quantify support for and against the null hypothesis: A flexible WinBUGS implementation of a default Bayesian t test

We propose a sampling-based Bayesian t test that allows researchers to quantify the statistical evidence in favor of the null hypothesis. This Savage—Dickey (SD) t test is inspired by the Jeffreys—Zellner—Siow (JZS) t test recently proposed by Rouder, Speckman, Sun, Morey, and Iverson (2009). The SD test retains the key concepts of the JZS test but is applicable to a wider range of statistical problems. The SD test allows researchers to test order restrictions and applies to two-sample situations in which the different groups do not share the same variance.     

Increase in counselling communication skills after basic and advanced microskills training

Background Mastering counselling communication skills is one of the requirements that lead to the diploma of a registered European psychologist. The microcounseling method proves to be effective in training these skills. Aim Research into the effectiveness of the microcounseling method often reports overall effect sizes only. The aim of this study was to investigate the adequate use of separate counselling communication skills (seven basic skills: minimal encouragements; asking questions; paraphrasing; reflection of feeling; concreteness; summarizing; and situation clarification and five advanced skills: advanced accurate empathy; confrontation; positive relabelling; examples of one's own; and directness) after respectively a basic and an advanced training in these skills. Sample Participants were 583 first year or second year bachelor students in psychology who took the counselling communication skills progress test (CSPT). The participants are divided in a group of freshmen, who had not received any training in counselling communication skills; first year students, who had received a training in basic skills; second year students who had followed a training in advanced skills and a control group. Method A between‐subject design, a within‐subject design and a pre‐test–post‐test‐control group design were used to examine the scores on these skills. Results Seven basic skills and four advanced skills had large effect sizes. One advanced skill had a moderate effect size. Conclusio The microcounseling method is very effective on the level of separate microskills. However, students perform better on the basic skills than on the advanced skills. More training seems to be needed in the latter to achieve the same level of mastery.     

Bootstrap confidence intervals in multi‐level simultaneous component analysis

Multi‐level simultaneous component analysis (MLSCA) was designed for the exploratory analysis of hierarchically ordered data. MLSCA specifies a component model for each level in the data, where appropriate constraints express possible similarities between groups of objects at a certain level, yielding four MLSCA variants. The present paper discusses different bootstrap strategies for estimating confidence intervals (CIs) on the individual parameters. In selecting a proper strategy, the main issues to address are the resampling scheme and the non‐uniqueness of the parameters. The resampling scheme depends on which level(s) in the hierarchy are considered random, and which fixed. The degree of non‐uniqueness depends on the MLSCA variant, and, in two variants, the extent to which the user exploits the transformational freedom. A comparative simulation study examines the quality of bootstrap CIs of different MLSCA parameters. Generally, the quality of bootstrap CIs appears to be good, provided the sample sizes are sufficient at each level that is considered to be random. The latter implies that if more than a single level is considered random, the total number of observations necessary to obtain reliable inferential information increases dramatically. An empirical example illustrates the use of bootstrap CIs in MLSCA.     

Three preparatory studies for promoting implementation of outpatient schema therapy for borderline personality disorder in general mental health care

ObjectiveThree studies were conducted to prepare for the implementation of Schema Therapy (ST) for Borderline Personality Disorder (BPD) in general mental healthcare settings. Two were surveys to detect promoting and hindering factors, one was a preliminary test of a training program in ST.MethodsIn 2004, a diagnostic analysis of factors promoting and hindering implementation of a new treatment for BPD was conducted among both managers (n = 23) and therapists (n = 49) of 29 Dutch mental healthcare institutes through a written survey (Study 1). Next, a training program, including a set of DVDs displaying the major therapeutic techniques, was developed and tested among eight therapists. The training program was evaluated by the participants. After the training, three independent raters evaluated therapists' adherence and competence, viewing videos of the therapists completing structured role-plays (Study 2). In 2008, a second written survey was conducted in 22 mental health institutes to study factors for future nationwide implementation of ST (Study 3).ResultsBoth surveys indicated that the situation in most institutes was favorable for implementing a new effective treatment, as participants were not satisfied with the existing treatments, had suitable professional backgrounds, worked in settings with (B)PD-oriented care programs, and expressed a need for change. The surveys yielded clear results for promoting or hindering successful implementation of ST. Promoting factors included scientific evidence for the effectiveness of the treatment, structural changes in the patient's personality, rapidly noticeable effects for the patient, low drop-out rates and a favorable cost-effectiveness. Possible barriers included implementation mandated unilaterally by management, choosing ST based on financial or organizational needs, extending implementation over a lengthy period of time and providing telephone support by therapists beyond office hours. The eight-day training program received very positive ratings. After the training, therapists were rated as sufficiently adherent and competent applying ST to treat BPD patients, with peer supervision and supervision recommended as a supplement to the training.ConclusionThis study showed that the situation in 2005 was advantageous to start implementation of ST. Evaluation of the training and the achieved competence scores of trainees concluded that the training program was a good basis for training therapists in ST. Outcome of the survey in 2008 demonstrated that there was a clear interest for implementation of ST for BPD patients in the future.     

"United We Stand, Divided We Fall"! The Protective Function of Self-Stereotyping for Stigmatised Members' Psychological Well-Being

Self-stereotyping is a process by which people who belong to a stigmatised social group tend to describe themselves more with both positive and negative stereotypical personality traits compared to traits that are irrelevant to the ingroup stereotype. A study is presented that shows how self-stereotyping serves to maintain psychological well-being among Southern Italian participants who suffer from an historical social stigma. Following the rejection-identification model ( Branscombe, Schmitt, & Harvey, 1999 ), perceptions of prejudice are directly negatively linked with well-being, but are compensated for via increased identification with the minority group that has a positive impact on psychological well-being. In the present study we propose that the compensatory role of ingroup identification on well-being is completely mediated by minority members' tendency to self-stereotype. A structural equation analysis provided support for this hypothesis. The present results highlight the importance of the self-stereotyping process in maintaining psychological well-being for members of low-status groups.     

Age differences in the prevalence of physical aggression among 5-11-year-old Canadian boys and girls

It has been proven extremely difficult in the past to estimate the prevalence of physical aggression in children for two main reasons: (a) a heterogeneous sampling of behaviors (i.e., mix between physically aggressive and non-physically aggressive antisocial behaviors), and (b) a lack of a "gold standard" to identify children who exhibit physically aggressive behaviors on a frequent basis. The goal of this study was to test for age differences in the prevalence of physical aggression in the Canadian population of school-aged boys and girls, using cross-sectional data from the National Longitudinal Survey of Children and Youth (NLSCY). The first wave of the NLSCY included a representative sample of 12,292 Canadian children aged 5-11 years. We used latent class analysis to identify children whose propensity to exhibit physically aggressive behaviors was much higher than that of other children of the same age and sex in the population. The prevalence of physical aggression was estimated at 3.7% in 5-11-year-old boys and ranged from .5% to 2.3% in 11 and 5-year-old girls, respectively. Hence, the results show a decreasing trend in the prevalence of physical aggression with age for girls, but not for boys. These findings suggest the importance of considering the developmental pathways of physical aggression for boys and girls separately.     

The contribution of covariation to skill improvement is an ambiguous measure: comment on Müller and Sternad (2004)

It has been proposed that it is possible to decompose changes in variability of human motor behavior into 3 independent components: covariation, task tolerance, and stochastic noise (H. Müller & D. Sternad). The authors simulate learning to throw accurately and show that for this task the proposed analysis does not give an unambiguous answer to the question of what the 3 components contribute to the simulated skill improvement. It is argued that this is caused by the fact that the component covariation depends on the choice of control variables. The authors conclude that it is not possible to distinguish between the 3 components of noise reduction without knowing the controlled variables.     

Mereology and time travel

Philosophical Studies - Core principles of mereology have been questioned by appealing to time travel scenarios. This paper questions the methodology of employing time travel scenarios to argue...