Repetition and Reconfiguration: Demand‐Based Confabulation in Initial Eyewitness Memory

Repeated recall, as a result of repeated questioning, is typical of situations involving eyewitness evidence. The present study addressed questions of eyewitness performance with reference to repeated questioning in an initial interview, in a format based on actual police procedures. This experiment focused on eyewitness accuracy, eyewitness confidence, and the addition of false details to eyewitness accounts. Ninety‐two adult respondents were asked to recall all the information they could from a single viewing of a scene depicting an assailant aiming a handgun at a victim. This initial question was followed by three additional questions, in which respondents were asked to report any additional details they could recall. On average, respondents provided several times as many correct as false details to the initial question. However, performance deteriorated significantly to the three subsequent questions; on average, across the three subsequent questions, witnesses recalled nearly as much false as accurate information. Witness confidence was positively related to amount of accurate information recalled. However, confidence was also positively related to the number of instances of erroneous recall. These results indicate that reconfigurative dynamics begin to operate, producing confabulated responses in response to questioning demands, as early as the initial interview. This work may also help to clarify the critical relationship between accuracy and confidence in eyewitness reportage, at least within the framework reflected by the present research. Copyright © 2012 John Wiley & Sons, Ltd.     

Fisher transformation based confidence intervals of correlations in fixed- and random-effects meta-analysis

Meta-analyses of correlation coefficients are an important technique to integrate results from many cross-sectional and longitudinal research designs. Uncertainty in pooled estimates is typically assessed with the help of confidence intervals, which can double as hypothesis tests for two-sided hypotheses about the underlying correlation. A standard approach to construct confidence intervals for the main effect is the Hedges-Olkin-Vevea Fisher-z (HOVz) approach, which is based on the Fisher-z transformation. Results from previous studies (Field, 2005, Psychol. Meth., 10, 444; Hafdahl and Williams, 2009, Psychol. Meth., 14, 24), however, indicate that in random-effects models the performance of the HOVz confidence interval can be unsatisfactory. To this end, we propose improvements of the HOVz approach, which are based on enhanced variance estimators for the main effect estimate. In order to study the coverage of the new confidence intervals in both fixed- and random-effects meta-analysis models, we perform an extensive simulation study, comparing them to established approaches. Data were generated via a truncated normal and beta distribution model. The results show that our newly proposed confidence intervals based on a Knapp-Hartung-type variance estimator or robust heteroscedasticity consistent sandwich estimators in combination with the integral z-to-r transformation (Hafdahl, 2009, Br. J. Math. Stat. Psychol., 62, 233) provide more accurate coverage than existing approaches in most scenarios, especially in the more appropriate beta distribution simulation model.     

Reliability coefficients for multiple group item response theory models

Reliability of scores from psychological or educational assessments provides important information regarding the precision of measurement. The reliability of scores is however population dependent and may vary across groups. In item response theory, this population dependence can be attributed to differential item functioning or to differences in the latent distributions between groups and needs to be accounted for when estimating the reliability of scores for different groups. Here, we introduce group-specific and overall reliability coefficients for sum scores and maximum likelihood ability estimates defined by a multiple group item response theory model. We derive confidence intervals using asymptotic theory and evaluate the empirical properties of estimators and the confidence intervals in a simulation study. The results show that the estimators are largely unbiased and that the confidence intervals are accurate with moderately large sample sizes. We exemplify the approach with the Montreal Cognitive Assessment (MoCA) in two groups defined by education level and give recommendations for applied work.     

认知诊断模型的标准误与置信区间估计：并行自助法

认知诊断模型的标准误(Standard Error, SE; 或方差—协方差矩阵)与置信区间(Confidence Interval, CI)在模型参数估计不确定性的度量、项目功能差异检验、项目水平上的模型比较、Q矩阵检验以及探索属性层级关系等领域有重要的理论与实践价值。本研究提出了两种新的SE和CI计算方法：并行参数化自助法和并行非参数化自助法。模拟研究发现：模型完全正确设定时, 在高质量及中等质量项目条件下, 这两种方法在计算模型参数的SE和CI时均有好的表现; 模型参数存在冗余时, 在高质量及中等质量项目条件下, 对于大部分允许存在的模型参数而言, 其SE和CI有好的表现。通过实证数据展示了新方法的价值及计算效率提升效果。     

Identifying the Effects of Unjustified Confidence versus Overconfidence: Lessons Learned from Two Analytic Methods

One of the most common findings in behavioral decision research is that people have unrealistic beliefs about how much they know. However, demonstrating that misplaced confidence exists does not necessarily mean that there are costs to it. This paper contrasts two approaches toward answering whether misplaced confidence is good or bad, which we have labeled the overconfidence and unjustified confidence approach. We first consider conceptual and analytic issues distinguishing these approaches. Then, we provide findings from a set of simulations designed to determine when the approaches produce different conclusions across a range of possible confidence–knowledge–outcome relationships. Finally, we illustrate the main findings from the simulations with three empirical examples drawn from our own data. We conclude that the unjustified confidence approach is typically the preferred approach, both because it is appropriate for testing a larger set of psychological mechanisms as well as for methodological reasons. Copyright © 2013 John Wiley & Sons, Ltd.     

Intrinsic goals for leisure-time physical activity predict children's daily step counts through autonomous motivation

ObjectivesThe present study tested a motivational sequence in which children's goals for leisure-time sport and physical activity (PA) from Goal Content Theory predicted pedometer-determined PA through behavioural regulation constructs from Self-Determination Theory.DesignQuantitative cross-sectional study.MethodsA sample of 1272 Flemish (Dutch speaking part of Belgium) sixth graders (M age = 11.42 years) filled in a questionnaire on PA goal content, behavioural regulations and pubertal status. Children's height and weight were measured to assess Body Mass Index (BMI). To measure daily PA behaviour, participants wore a pedometer for seven consecutive days. Structural equation modelling was performed to test the proposed motivational sequence and to examine the mediation effect of behavioural regulations towards leisure-time sport and PA on the relation between PA goal content and daily step counts.ResultsA structural equation model supported the hypothesized sequence in which intrinsic goals for leisure-time sport and PA predicted children's daily step counts through autonomous motivation towards leisure-time sport and PA. Multi-sample invariance testing revealed that the proposed model was largely invariant across BMI groups, pubertal status and gender.ConclusionsThe findings highlight the importance of emphasizing intrinsic goals for participation in leisure-time sport and PA in children aged 10–12 years. By stimulating children to participate in PA and sports by referring to intrinsic goals, children are more likely to enjoy PA, which in turn might increase the likelihood of a regular and long-term PA engagement.     

Situationally Equivocal Eyewitness Evidence and the Violence of Crimes

Eyewitness evidence is amongst the most important types of evidence in investigative and juridical proceedings. Yet, eyewitness evidence frequently derives from observations made under situationally equivocal conditions, including such factors as darkness and physical obstruction of view. The effect of the violence of a given crime on potential jurors' evaluation of such equivocal evidence was addressed. A witness's identification of a suspect in a violent crime was generated in three versions, varying only in the level of violence of the crime. Respondents were more likely to accept this identification as accurate under more violent conditions and were also less likely to report noticing or considering equivocal aspects (darkness and physical obstruction) in situations of greater violence. Predisposing factors to judgement of guilt lay significantly in the acceptance of punishment as a viable deterrent to crime and of societal guilt for the criminal's behaviour, although political or religious orientations were not shown to influence these results, and none of these factors interacted with the violence of the crime to influence judgement of guilt or innocence. These findings indicate the importance of affective factors in judgements of guilt or innocence, especially when these judgements are based on situationally equivocal eyewitness evidence. Copyright © 2013 John Wiley & Sons, Ltd.     

The effects of repeatedly recalling a traumatic event on eyewitness memory and suggestibility

ABSTRACT

The aims of this study were to examine the effects of repeatedly recalling a traumatic event on recall performance and eyewitness suggestibility. We also investigated whether these effects were moderated by the type of details recalled and the completeness of retrieval. Participants watched a video depicting a fatal car accident and were randomly allocated to one of four conditions in which they: (1) repeatedly recalled the traumatic (central) details of the event only (trauma-focused); (2) repeatedly recalled the non-traumatic (peripheral) details of the event only (non-trauma focused); (3) repeatedly recalled the entire video (complete); or (4) did not recall the video at all (no-recall control). Results indicated that repeated complete recall was beneficial for memory retention of the entire traumatic event and that, in general, trauma-related (central) post-event information (PEI) was less likely to be reported than trauma-unrelated (peripheral) PEI. It was also found that repeated trauma-focused recall increased trauma-related confabulations. These results not only illustrate the value of repeated complete recall to best preserve the integrity of eyewitness memory, but, perhaps more critically, warn of the dangers of repeatedly questioning witnesses specifically about the central or traumatic details of an event.     

Children's eyewitness memory: Repeating post-event misinformation reduces the distinctiveness of a witnessed event

Children may incorporate misinformation into reports of witnessed events, particularly if the misinformation is repeated. One explanation is that the misinformation trace is strengthened by repetition. Alternatively, repeating misinformation may reduce the discriminability between event and misinformation sources, increasing interference between them. We tested trace strength and distinctiveness accounts by showing 5- and 6-year-olds an event and then presenting either the “same” or “varying” items of post-event misinformation across three iterations. Performance was compared to a baseline in which misinformation was presented once. Repeating the same misinformation increased suggestibility when misinformation was erroneously attributed to both event and misinformation sources, supporting a trace strength interpretation. However, suggestibility measured by attributing misinformation solely to the event, was lower when misinformation was presented repeatedly rather than once. In contrast, identification of the correct source of the event was less likely if the misinformation was repeated, whether the same or different across iterations. Thus a reduction in the distinctiveness of sources disrupted memory for the event source. Moreover, there was strong association between memory for the event and a measure of distinctiveness of sources, which takes into account both the number of confusable source and their apparent temporal spacing from the point of retrieval.