How many trials are required for parameter estimation in diffusion modeling? A comparison of different optimization criteria

Diffusion models (Ratcliff, 1978) make it possible to identify and separate different cognitive processes underlying responses in binary decision tasks (e.g., the speed of information accumulation vs. the degree of response conservatism). This becomes possible because of the high degree of information utilization involved. Not only mean response times or error rates are used for the parameter estimation, but also the response time distributions of both correct and error responses. In a series of simulation studies, the efficiency and robustness of parameter recovery were compared for models differing in complexity (i.e., in numbers of free parameters) and trial numbers (ranging from 24 to 5,000) using three different optimization criteria (maximum likelihood, Kolmogorov–Smirnov, and chi-square) that are all implemented in the latest version of fast-dm (Voss, Voss, & Lerche, 2015). The results revealed that maximum likelihood is superior for uncontaminated data, but in the presence of fast contaminants, Kolmogorov–Smirnov outperforms the other two methods. For most conditions, chi-square-based parameter estimations lead to less precise results than the other optimization criteria. The performance of the fast-dm methods was compared to the EZ approach (Wagenmakers, van der Maas, & Grasman, 2007) and to a Bayesian implementation (Wiecki, Sofer, & Frank, 2013). Recommendations for trial numbers are derived from the results for models of different complexities. Interestingly, under certain conditions even small numbers of trials (N < 100) are sufficient for robust parameter estimation.     

Holos: A collaborative environment for similarity-based holistic approaches

Through this article, we aim to introduce Holos—a new collaborative environment that allows researchers to carry out experiments based on similarity assessments between stimuli, such as in projective-mapping and sorting tasks. An important feature of Holos is its capacity to assess real-time individual processes during the task. Within the Holos environment, researchers can design experiments on its platform, which can handle four kinds of stimuli: concepts, images, sounds, and videos. In addition, researchers can share their study resources within the scientific community, including stimuli, experimental protocols, and/or the data collected. With a dedicated Android application combined with a tactile human–machine interface, subjects can perform experiments using a tablet to obtain similarity measures between stimuli. On the tablet, the stimuli are displayed as icons that can be dragged with one finger to position them, depending on the ways they are perceived. By recording the x,y coordinates of the stimuli while subjects move the icons, the obtained data can reveal the cognitive processes of the subjects during the experiment. Such data, named digit-tracking data, can be analyzed with the SensoMineR package. In this article, we describe how researchers can design an experiment, how subjects can perform the experiment, and how digit-tracking data can be statistically analyzed within the Holos environment. At the end of the article, a short exemplary experiment is presented.     

The state of web-based research: A survey and call for inclusion in curricula

The first papers that reported on conducting psychological research on the web were presented at the Society for Computers in Psychology conference 20 years ago, in 1996. Since that time, there has been an explosive increase in the number of studies that use the web for data collection. As such, it seems a good time, 20 years on, to examine the health and adoption of sound practices of research on the web. The number of studies conducted online has increased dramatically. Overall, it seems that the web can be a method for conducting valid psychological studies. However, it is less clear that students and researchers are aware of the nature of web research. While many studies are well conducted, there is also a certain laxness appearing regarding the design and conduct of online studies. This laxness appears both anecdotally to the authors as managers of large sites for posting links to online studies, and in a survey of current researchers. One of the deficiencies discovered is that there is no coherent approach to educating researchers as to the unique features of web research.     

Predictors of Secondary School Completion Among Refugee Youth 8 to 9 Years After Resettlement in Melbourne,Australia

Being able to attend school and achieve an education is one of the most desired opportunities among resettled refugee young people. However, turning educational aspirations into reality is not straightforward. There is a large body of research documenting the barriers associated with educational achievement among refugees who resettle as teenagers, both in Australia and internationally. No studies, however, have identified the factors that predict completion of secondary school among resettled refugee youth over time. This paper reports the predictors of completion of secondary school among a cohort of 47 refugee youth resettled in Melbourne, Australia. Eight to 9 years after resettlement, 29 (62 %) had completed secondary school and 18 (38 %) had left school prior to completing year 12. Age on arrival and experiences of discrimination in Australia were significant predictors of secondary school completion. Older refugee youth (on arrival) and those who reported experiences of discrimination over the first 8 to 9 years in Australia were significantly less likely to complete secondary school. This longitudinal study confirms that, as a group, refugee youth are particularly at risk of not completing secondary school education, which can have an impact on their wellbeing and long-term socio-economic standing in their settlement country. Our study provides further evidence of the negative impact of discrimination on the educational outcomes of disadvantaged young people.     

Predicting Successful Responses to Emergencies: the Emergency Responsiveness Scale

People respond to disasters in a variety of ways. Some individuals respond to disasters or emergencies with panicked activity while others mobilize resources without panicking. In this article, we propose that the individual response to emergencies is determined by Emergency Responsiveness, the manner in which an individual appraises an emergency situation. We believe Emergency Responsiveness consists of four factors: Risk Taking, Experience with Emergencies, Emergency Anxiety, and Emergency Preparation. In Study One, each of the four subscales of Emergency Responsiveness correlated with personality traits in the hypothesized directions, providing evidence of construct validity. In Study Two, we establish criterion-related validity by demonstrating that a sample of first-responders scored significantly higher than a control sample on all four dimensions. Our results support our hypothesis that Emergency Responsiveness is a measurable individual difference. Implications for first responders and emergency services are discussed.     

Mediator Roles of Interpersonal Forgiveness and Self-Forgiveness between Self-Esteem and Subjective well-Being

This study examined the effect of self-esteem on subjective well-being, with focus on confirmation of mediator roles of interpersonal forgiveness and self-forgiveness among a sample of 475 college students. The participants completed a questionnaire packet that includes Rosenberg Self-Esteem Scale, Heartland Forgiveness Scale, and Subjective Well-Being Scale. Results revealed that self-esteem, interpersonal forgiveness, and self-forgiveness were all significantly correlated with subjective well-being. Bootstrap results indicated that both interpersonal forgiveness and self-forgiveness partially mediated self-esteem to subjective well-being. Structural equation modeling analysis also revealed significant paths from self-esteem to subjective well-being through both interpersonal forgiveness and self-forgiveness.     

Social Functioning and Coping Strategies in Romanian and Moldavian Adolescents with Chronic Diseases

The present study aimed to explore the cultural differences in social functioning and coping strategies in chronically ill adolescents. One hundred sixty-eight chronically ill adolescents (45.8 % girls), age 11 to 17 years from Romania (N = 78) and Republic of Moldova (N = 90) were recruited. Participants filled in self-assessment measures for social functioning problems and coping strategies. Results indicated cross-cultural differences in the studied factors: Moldavian adolescents reported more social functioning problems and higher use of maladaptive coping strategies, while using less adaptive strategies than Romanian counterparts. The associations between social functioning and maladaptive coping strategies were stronger for Romanian than Moldavian adolescents. Further, various coping strategies acted as important predictors for social functioning in the two country samples. Findings suggest that, while the direction of the relation between coping and social functioning in chronically ill adolescents is cultural invariant, the importance played by specific coping strategies in determining social functioning varies by cultural context. Therefore, clinical interventions aimed at improving the social functioning of chronically ill adolescents should take into account the reality of their cultural setting.     

The Relationship between Psychological Capital,Coping with Stress,Well-Being,and Performance

This study examined coping with stress from an organizational perspective by positing a relationship between Psychological Capital (PsyCap) and coping strategies (defined as change, accepting, or withdrawal). It was hypothesized that coping strategies would mediate the relationship between PsyCap and people’s well-being and performance. Questionnaire findings from a five hundred and fifty four employees showed a significant relationship between PsyCap and coping. Coping strategy in terms of change partially mediated the relationship between PsyCap and the outcomes of well-being and performance. Coping strategy in terms of withdrawal partially mediated the relationship between PsyCap and performance. PsyCap was found to have a strong, positive, and direct correlation with well-being and performance. Well-being was not found to associate significantly with performance. These findings suggest that the central variable in the model is not coping but PsyCap. PsyCap appears to have a strong, direct, and significant effect on the dependent variables. The theoretical implications are examined and future research avenues suggested.     

Changing Definitions of Work and Play: Importance of Workplace Humour

World famous actor-comedian Charlie Chaplin once said that “A day without laughter is a day wasted”. But try applying the same quote in our work place, with fluctuating markets, unending competition and impossible deadlines; we may find more wasted days than the rest. All of us know what it feels to experience humour, but most of us think twice before having a hearty laugh at our workplace. What is the barrier which stops us from sharing humour at work? This paper attempts to answer this question and aims to understand the concept of humour at workplace and its importance in today’s context. It aims to review existing literature in this field and present the application of Workplace humour in an organizational context to achieve favourable work-related outcomes. In addition to this, the paper also enumerates the different workplace practices that are directly or indirectly related to humour and provide suggestions to organizations on how to use this powerful tool to bring about organizational effectiveness.