Bayesian inference for psychology. Part II: Example applications with JASP

Bayesian hypothesis testing presents an attractive alternative to p value hypothesis testing. Part I of this series outlined several advantages of Bayesian hypothesis testing, including the ability to quantify evidence and the ability to monitor and update this evidence as data come in, without the need to know the intention with which the data were collected. Despite these and other practical advantages, Bayesian hypothesis tests are still reported relatively rarely. An important impediment to the widespread adoption of Bayesian tests is arguably the lack of user-friendly software for the run-of-the-mill statistical problems that confront psychologists for the analysis of almost every experiment: the t-test, ANOVA, correlation, regression, and contingency tables. In Part II of this series we introduce JASP (http://www.jasp-stats.org), an open-source, cross-platform, user-friendly graphical software package that allows users to carry out Bayesian hypothesis tests for standard statistical problems. JASP is based in part on the Bayesian analyses implemented in Morey and Rouder’s BayesFactor package for R. Armed with JASP, the practical advantages of Bayesian hypothesis testing are only a mouse click away.     

Bayesian inference for psychology. Part I: Theoretical advantages and practical ramifications

Bayesian parameter estimation and Bayesian hypothesis testing present attractive alternatives to classical inference using confidence intervals and p values. In part I of this series we outline ten prominent advantages of the Bayesian approach. Many of these advantages translate to concrete opportunities for pragmatic researchers. For instance, Bayesian hypothesis testing allows researchers to quantify evidence and monitor its progression as data come in, without needing to know the intention with which the data were collected. We end by countering several objections to Bayesian hypothesis testing. Part II of this series discusses JASP, a free and open source software program that makes it easy to conduct Bayesian estimation and testing for a range of popular statistical scenarios (Wagenmakers et al. this issue).     

Preparatory processes in the task-switching paradigm: evidence from the use of probability cues

The purpose of the investigations was to dissociate processes of task preparation from task execution in the task-switching paradigm. The basic assumption was that task repetitions have 2 advantages over task shifts: an activation advantage as a result of the execution of the same task type in the pretrial, and an expectation advantage, because participants, in general, implicitly expect a repetition. In Experiments 1-3, the authors explicitly manipulated expectancies by presenting cues that announced a shift and/or a repetition with probabilities of 1.00, .75, .50, or .25. Increasing latencies with decreasing probability for shifts and repetitions show that the expectation advantage can be equalized by preparation. However, the activation advantage represented by constant shift costs between tasks of the same probability is not penetrable by preparation. In Experiments 4 and 5, the authors found evidence that preparation involves activation of the expected task and inhibition of distracting tasks.     

Catch me if I fall! Enacted uncertainty avoidance and the social safety net as country-level moderators in the job insecurity-job attitudes link

Job insecurity is related to many detrimental outcomes, with reduced job satisfaction and affective organizational commitment being the 2 most prominent reactions. Yet, effect sizes vary greatly, suggesting the presence of moderator variables. On the basis of Lazarus's cognitive appraisal theory, we assumed that country-level enacted uncertainty avoidance and a country's social safety net would affect an individual's appraisal of job insecurity. More specifically, we hypothesized that these 2 country-level variables would buffer the negative relationships between job insecurity and the 2 aforementioned job attitudes. Combining 3 different data sources, we tested the hypotheses in a sample of 15,200 employees from 24 countries by applying multilevel modeling. The results confirmed the hypotheses that both enacted uncertainty avoidance and the social safety net act as cross-level buffer variables. Furthermore, our data revealed that the 2 cross-level interactions share variance in explaining the 2 job attitudes. Our study responds to calls to look at stress processes from a multilevel perspective and highlights the potential importance of governmental regulation when it comes to individual stress processes.     

Frustration Intolerance Beliefs as Predictors of Emotional Problems in University Undergraduates

The present study examined the relationship between Frustration Intolerance Beliefs as suggested by the Rational Emotive Behavior Therapy framework and emotional problems. Data were collected from 332 university undergraduate students (age 19–26) who completed Demographic Information Sheet, Frustration Discomfort Scale and three subscales of Brief Symptom Inventory including depression, anxiety and hostility. The current findings confirmed the association between frustration intolerance and irrational beliefs and their respective roles in psychological distress among non-clinical student population. Results indicated that FDS subscales were differently related to specific emotions as entitlement and emotional intolerance sub-scales were significantly positively associated with depression, anxiety, and hostility while achievement was significantly negatively associated with hostility. The study has implications for counsellors, school psychologists and policy makers as it highlights the importance of rational group and individual counselling of rational ideas to reduce the emotional problems of students hindering their educational and personal growth.     

The “Not Letting Go” phenomenon: accuracy instructions can impair behavioral and metacognitive effects of implicit learning processes

One major assumption in the field of implicit learning is that implicit learning processes directly affect performance without further top-down control (e.g., Destrebecqz and Cleeremans 2003). In three related experiments, the authors tested the so-called “Not Letting Go Phenomenon” (Schneider and Fisk in J Exp Psychol Learn Mem Cogn 8:261–278, 1982); that is, the assumption that accuracy instructions might impair the effect of implicit learning processes during skill acquisition. Results of Experiment 1 show that accuracy instructions can impair both, the behavioral and metacognitive effects of implicit learning. Experiments 2 and 3 indicate that this impairment is due more to an impairment of the performance effects of implicit learning processes than to a direct impairment of the learning processes, per se. While these results are in accordance with recent findings in skill acquisition showing that monitoring processes impede experts’ performance, they seem to contradict the above mentioned assumption that implicit learning processes directly affect performance.

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The generation of conscious awareness in an incidental learning situation

The purpose of the present experiments was to investigate the generation of conscious awareness (i.e., of verbal report) in an incidental learning situation. While the single-system account assumes that all markers of learning, verbal or nonverbal, index the same underlying knowledge representation, multiple-systems accounts grant verbal report a special status as a marker of learning because they assume that the nonverbal and verbal effects of learning rely on different memory representations. We tested these two accounts in two experiments in which we held the amount of learning in the nonverbal memory system constant while manipulating independent variables aimed at affecting learning in the declarative system. The results of both experiments revealed significant differences in verbal report between experimental conditions, but no significant differences in response times. Overall, these results provide clear evidence in favor of the multiple-systems account.     

Are strategy shifts caused by data-driven processes or by voluntary processes?

The present research investigates the role of voluntary, conscious processing in strategy change. In 2 experiments, we address whether the switch to a new strategy is the result of data-driven, automatic processes or of voluntary processes. Experiment 1 demonstrates that participants performing an alphabet verification task are able to (a) transfer a newly adopted strategy to dissimilar information never encountered before, (b) verbally describe the task regularity that allows for the generation and application of the new strategy immediately after the strategy was adopted. Using the same experimental task, Experiment 2 shows that participants, and (c) decide against adopting a new strategy when the available evidence suggests that the new strategy cannot be used for the entire range of problems encountered. Overall, the obtained results support the view that strategy change is mediated by voluntary controlled processing. They do not support the view that strategy change is an inevitable, automatic consequence of task practice. The present research thus highlights a potential function of conscious human processing.