Hidden Markov Item Response Theory Models for Responses and Response Times

Current approaches to model responses and response times to psychometric tests solely focus on between-subject differences in speed and ability. Within subjects, speed and ability are assumed to be constants. Violations of this assumption are generally absorbed in the residual of the model. As a result, within-subject departures from the between-subject speed and ability level remain undetected. These departures may be of interest to the researcher as they reflect differences in the response processes adopted on the items of a test. In this article, we propose a dynamic approach for responses and response times based on hidden Markov modeling to account for within-subject differences in responses and response times. A simulation study is conducted to demonstrate acceptable parameter recovery and acceptable performance of various fit indices in distinguishing between different models. In addition, both a confirmatory and an exploratory application are presented to demonstrate the practical value of the modeling approach.     

A semi-parametric within-subject mixture approach to the analyses of responses and response times

In item response theory, modelling the item response times in addition to the item responses may improve the detection of possible between- and within-subject differences in the process that resulted in the responses. For instance, if respondents rely on rapid guessing on some items but not on all, the joint distribution of the responses and response times will be a multivariate within-subject mixture distribution. Suitable parametric methods to detect these within-subject differences have been proposed. In these approaches, a distribution needs to be assumed for the within-class response times. In this paper, it is demonstrated that these parametric within-subject approaches may produce false positives and biased parameter estimates if the assumption concerning the response time distribution is violated. A semi-parametric approach is proposed which resorts to categorized response times. This approach is shown to hardly produce false positives and parameter bias. In addition, the semi-parametric approach results in approximately the same power as the parametric approach.     

Book Reviews

For inexperienced sales representatives, success provides an important learning opportunity from which to build confidence and hone strategies. Such learning is derived from the attributions one makes for success and how those attributions shape future behavior. This research investigates the interpretation and behavioral intentions of inexperienced sales representatives following a successful sales call using a sample of financial services representatives. Surprisingly, we found that achieving success did not assure the adoption or future use of the strategy that garnered that success. These results suggest that inexperienced sales representatives may require managerial attention to fully understand and appropriately assimilate their sales successes. Implications for managers and future research are discussed.     

The Houdini Transformation: True,but Illusory

Molenaar (2003, 2011) showed that a common factor model could be transformed into an equivalent model without factors, involving only observed variables and residual errors. He called this invertible transformation the Houdini transformation. His derivation involved concepts from time series and state space theory. This article verifies the Houdini transformation on a general latent variable model using algebraic methods. The results show that the Houdini transformation is illusory in the sense that the Houdini-transformed model remains a latent variable model. Contrary to common knowledge, a model that is a path model with only observed variables and residual errors may, in fact, be a latent variable model.     

God knows (but does God believe?)

The standard view in epistemology is that propositional knowledge entails belief. Positive arguments are seldom given for this entailment thesis, however; instead, its truth is typically assumed. Against the entailment thesis, Myers-Schulz and Schwitzgebel (Noûs, forthcoming) report that a non-trivial percentage of people think that there can be propositional knowledge without belief. In this paper, we add further fuel to the fire, presenting the results of four new studies. Based on our results, we argue that the entailment thesis does not deserve the default status that it is typically granted. We conclude by considering the alternative account of knowledge that Myers-Schulz and Schwitzgebel propose to explain their results, arguing that it does not explain ours. In its place we offer a different explanation of both sets of findings—the conviction account, according to which belief, but not knowledge, requires mental assent.     

Secure attachment and material reward both attenuate romantic jealousy

Research has shown that social support and materialism can both serve as coping mechanisms, reducing individuals’ experiences of physical and social pain (Zhou and Gao in Psychol Inq 19(3–4):127–144, 2008). We extend this paradigm by testing the buffering effects of secure attachment and material reward on a specific form of social psychological pain: romantic jealousy. Two studies examined the effects of these variables after an imagined relational threat. Participants were primed with (a) secure attachment, (b) material reward, or (c) neutral control, and then responded to a hypothetical scenario involving their romantic partners behaving flirtatiously with a rival. Results from both studies showed that the secure attachment and material reward primes both attenuated jealous responses to the provoking stimuli, relative to the neutral control prime. Neither trait attachment styles nor chronic jealousy moderated the priming effects in Study 1, but attachment styles did slightly moderate the priming effects in Study 2.     

Examining the association between MAOA genotype and incarceration, anger and hostility: The moderating influences of risk and protective factors

Findings from molecular genetic research have indicated that a polymorphism in the promoter region of the MAOA gene interacts with environmental liabilities to predict antisocial phenotypes. We use these findings as a springboard to examine whether a global protective-risk factor index moderates the effect of MAOA genotype on the probability of being incarcerated and on a measure of anger and hostility. Analysis of data from the National Longitudinal Study of Adolescent Health (Add Health) indicates that exposure to risk and protective factors in adolescence are able to moderate the effect of MAOA genotype on anger and hostility in adulthood for males. The results in relation to the probability of being incarcerated were consistently null.     

Socrates,Crito, and emigration from South Africa

This article uses Plato’s Crito as a lens through which to consider the question of whether a South African citizen should emigrate from South Africa. While this question is not exactly parallel to that of whether the condemned Socrates should flee Athens, it has much more to do with justice than is commonly thought. For in order for one to know whether one has an overall duty to remain in or leave South Africa, one must determine what one owes to one’s country and compatriots, one’s community, one’s family, and oneself.     

Effects of Manipulation on Attributions of Causation,Free Will,and Moral Responsibility

If someone brings about an outcome without intending to, is she causally and morally responsible for it? What if she acts intentionally, but as the result of manipulation by another agent? Previous research has shown that an agent's mental states can affect attributions of causal and moral responsibility to that agent , but little is known about what effect one agent's mental states can have on attributions to another agent. In Experiment 1, we replicate findings that manipulation lowers attributions of responsibility to manipulated agents. Experiments 2–7 isolate which features of manipulation drive this effect, a crucial issue for both philosophical debates about free will and attributions of responsibility in situations involving social influence more generally. Our results suggest that “bypassing” a manipulated agent's mental states generates the greatest reduction in responsibility, and we explain our results in terms of the effects that one agent's mental states can have on the counterfactual relations between another agent and an outcome.