Interval estimation for the intraclass correlation in dirichlet-multinomial data

When the underlying distribution is discrete with a limited number of categories, methods for interval estimation of the intraclass correlation which assume normality are theoretically inadequate for use. On the basis of large sample theory, this paper develops an asymptotic closed-form interval estimate of the intraclass correlation for the case where there is a natural score associated with each category. This paper employs Monte Carlo simulation to demonstrate that when the underlying intraclass correlation is large, the traditional interval estimator which assumes normality can be misleading. We find that when the number of classes is 20, the interval estimator proposed here can generally perform reasonably well in a variety of situations. This paper further notes that the proposed interval estimator is invariant with respect to a linear transformation. When the data are on a nominal scale, an extension of the proposed method to account for this case, as well as a discussion on the relationship between the intraclass correlation and a kappa-type measure defined here and on the limitation of the corresponding kappa-type estimator are given.The authors wish to thank the Editor, the Associate Editor, and the three referees for many valuable comments and suggestions to improve the clarity of this paper. The works for the first, the third, and the fourth authors were partially supported by grant #R01AR43025-01 from the National Institute of Arthritis and Musculoskeletal and Skin Diseases.     

On the sampling interpretation of confidence intervals and hypothesis tests in the context of conditional maximum likelihood estimation

In the context ofconditional maximum likelihood (CML) estimation, confidence intervals can be interpreted in three different ways, depending on the sampling distribution under which these confidence intervals contain the true parameter value with a certain probability. These sampling distributions are (a) the distribution of the data given theincidental parameters, (b) the marginal distribution of the data (i.e., with the incidental parameters integrated out), and (c) the conditional distribution of the data given the sufficient statistics for the incidental parameters. Results on the asymptotic distribution of CML estimates under sampling scheme (c) can be used to construct asymptotic confidence intervals using only the CML estimates. This is not possible for the results on the asymptotic distribution under sampling schemes (a) and (b). However, it is shown that theconditional asymptotic confidence intervals are also valid under the other two sampling schemes. I am indebted to Theo Eggen, Norman Verhelst and one of Psychometrika's reviewers for their helpful comments.     

Effect of the violation of normality and sphericity in the linear mixed model in split-plot designs

This study aimed to evaluate the robustness of the linear mixed model, with the Kenward-Roger correction for degrees of freedom, when implemented in SAS PROC MIXED, using split-plot designs with small sample sizes. A Monte Carlo simulation design involving three groups and four repeated measures was used, assuming an unstructured covariance matrix to generate the data. The study variables were: sphericity, with epsilon values of 0.75 and 0.57; group sizes, equal or unequal; and shape of the distribution. As regards the latter, non-normal distributions were introduced, combining different values of kurtosis in each group. In the case of unbalanced designs, the effect of pairing (positive or negative) the degree of kurtosis with group size was also analysed. The results show that the Kenward-Roger procedure is liberal, particularly for the interaction effect, under certain conditions in which normality is violated. The relationship between the values of kurtosis in the groups and the pairing of kurtosis with group size are found to be relevant variables to take into account when applying this procedure.     

Robust estimation of the hierarchical model for responses and response times

Van der Linden's (2007, Psychometrika, 72, 287) hierarchical model for responses and response times in tests has numerous applications in psychological assessment. The success of these applications requires the parameters of the model to have been estimated without bias. The data used for model fitting, however, are often contaminated, for example, by rapid guesses or lapses of attention. This distorts the parameter estimates. In the present paper, a novel estimation approach is proposed that is robust against contamination. The approach consists of two steps. In the first step, the response time model is fitted on the basis of a robust estimate of the covariance matrix. In the second step, the item response model is extended to a mixture model, which allows for a proportion of irregular responses in the data. The parameters of the mixture model are then estimated with a modified marginal maximum likelihood estimator. The modified marginal maximum likelihood estimator downweights responses of test-takers with unusual response time patterns. As a result, the estimator is resistant to several forms of data contamination. The robustness of the approach is investigated in a simulation study. An application of the estimator is demonstrated with real data.     

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.     

Global self-evaluations and perceived instability of self in early adolescence: A cohort longitudinal study

A cohort longitudinal design with four adjacent cohorts of students ( n = 1689) followed over two years was used to study key issues identified in the research literature on the development of self-evaluations in early adolescence. There was no clear relationship between age/grade and self-evaluations. We found no support for a "stressful periods" hypothesis with respect to self: Possible changes were very gradual and quite small. However, there was a consistent "relative age" effect implying that younger students within a grade had more negative self-evaluations. There were small but consistent sex differences in self-evaluations in favor of the boys; more detailed analyses of very negative self-evaluations suggested that the early adolescent years are the period in which a sex difference in depression related symptomatology begins to emerge. Finally, the usefulness of some kind of effect size measure and advantages and problems associated with a cohort longitudinal design were discussed.     

Change in school ethnic diversity and intergroup relations: The transition from segregated elementary to mixed secondary school for majority and minority students

This research examined the impact of a change in school diversity on school children's intergroup relations. A longitudinal survey tracked 551 White British and Asian British students (M_age = 11.32) transitioning from elementary (time 1) to secondary (time 2) school in an ethnically segregated town in the United Kingdom. We estimated a multivariate, multilevel model. A cross-sectional comparison of segregated schools and a mixed elementary school at time 1 revealed that both Asian and White British in the mixed school reported more positive intergroup relations. A longitudinal analysis found that the transition from segregated elementary to mixed secondary schools was associated with Asian British developing more positive intergroup relations. White British reported overall less positive intergroup relations, although only trust decreased; evidence from other measures remains inconclusive. The findings are important for understanding early stages of diversity exposure, and the impact of changing diversity levels on majority and minority groups.     

The development of numerosity estimation: Evidence for a linear number representation early in life

Several studies investigating the development of approximate number representations used the number-to-position task and reported evidence for a shift from a logarithmic to a linear representation of numerical magnitude with increasing age. However, this interpretation as well as the number-to-position method itself has been questioned recently. The current study tested 5- and 8-year-old children on a newly established numerosity production task to examine developmental changes in number representations and to test the idea of a representational shift. Modelling of the children's numerical estimations revealed that responses of the 8-year-old children approximate a simple positive linear relation between estimated and actual numbers. Interestingly, however, the estimations of the 5-year-old children were best described by a bilinear model reflecting a relatively accurate linear representation of small numbers and no apparent magnitude knowledge for large numbers. Taken together, our findings provide no support for a shift of mental representations from a logarithmic to a linear metric but rather suggest that the range of number words which are appropriately conceptualised and represented by linear analogue magnitude codes expands during development.     

Prevalence of interactions and influence of performance constraints on kick outcomes across Australian Football tiers: Implications for representative practice designs

Representative learning design is a key feature of the theory of ecological dynamics, conceptualising how task constraints can be manipulated in training designs to help athletes self-regulate during their interactions with information-rich performance environments. Implementation of analytical methodologies can support representative designs of practice environments by practitioners recording how interacting constraints influence events, that emerge under performance conditions. To determine key task constraints on kicking skill performance, the extent to which interactions of constraints differ in prevalence and influence on kicking skills was investigated across competition tiers in Australian Football (AF).A data sample of kicks (n = 29,153) was collected during junior, state-level and national league matches. Key task constraints were recorded for each kick, with performance outcome recorded as effective or ineffective. Rules were based on frequency and strength of associations between constraints and kick outcomes, generated using the Apriori algorithm.Univariate analysis revealed that low kicking effectiveness was associated with physical pressure (37%), whereas high efficiency emerged when kicking to an open target (70%). Between-competition comparisons showed differences in constraint interactions through seven unique rules and differences in confidence levels in shared rules.Results showed how understanding of key constraints interactions, and prevalence during competitive performance, can be used to inform representative learning designs in athlete training programmes. Findings can be used to specify how the competitive performance environment differs between competition tiers, supporting the specification of information in training designs, representative of different performance levels.     

Behavioural analysis of interactions between pedestrians and vehicles in street designs with elements of shared space

This paper describes the development and implementation of qualitative behavioural criteria in order to analyse the conduct of pedestrians and vehicles when they are required to interact with each other, with particular interest to street designs with elements of shared space. The new behavioural analysis technique is developed by identifying the fundamental principles that underpin existing traffic analyses, such as traffic conflicts techniques, and adapting those to a qualitative framework that describes the mindset and rationale of road users. The technique is then applied to a case study in London, using video data from periods before and after the redevelopment of the Exhibition Road site from a conventional dual carriageway to a modern design with some elements of shared space. With the main goals being to assess the pedestrians’ confidence and the vehicles’ tolerance/patience when forced to interact with each other, behavioural trends are related to instantaneous characteristics of the vehicle flow (vehicle approach speed and traffic density). The data produced are used to develop and validate qualitative behavioural relationships for pedestrian–vehicle interactions, as well as location-specific conclusions for the Exhibition Road site.     

Swimming against the tide: the changing functions and status of chaplains in the Israel Defense Force

This article describes and analyses the changes that have occurred in the services performed by chaplains in the Israel Defense Force (IDF) – the only military in the world that consists almost entirely of Jews. Essentially, we argue, the shift has been one of focus. For many years, IDF chaplains primarily (albeit never exclusively) concerned themselves with providing religious services to the minority of personnel who observed Orthodox Jewish rituals. ‘Outreach’ programmes, targeted at the secular Jewish majority, were secondary. Recently, however, the IDF rabbinate has undergone a process of ‘role expansion’, emphasising the provision of counselling and guidance to the entire Jewish complement, especially in combat units. In the second part of the article, we analyse the possible reasons for that development: demographic and cultural trends in Israeli society; the prominence of counter-insurgency missions in the IDF’s operational agenda; and the personalities of recent chief chaplains. Finally, we address the possible implications of this shift, asking whether the intra-organisational frictions that it generates, especially with the Education Corps, portends a battle for the soul of the IDF.     

Convergent and Discriminant Validity of Trait and Source Effects in ADHD-Inattention and Hyperactivity/Impulsivity Measures Across a 3-Month Interval

Confirmatory factor analysis was used to model a multitrait (ADHD-inattention and hyperactivity/ impulsivity) by multisource (teachers and parents) design across a 3-month interval in a sample of 360 Australian elementary school children. The purpose was to evaluate the convergent and discriminant validity of the ADHD-inattention (IN) and hyperactivity/impulsivity (H/I) measures. Although similar traits and similar sources showed stronger correlations across time than dissimilar traits and dissimilar sources, the amount of source variance in the ADHD-IN and ADHD-H/I measures was substantial and consistent across the interval (M = 59%; range = 35–84%). This large amount of source variance raises the possibility that the correlations of the IN and H/I rating scales with other constructs (e.g., social competence, conduct problems) represent mostly source rather than trait effects. Multitrait by multisource analyses provide a means to answer this question and further advance understanding of ADHD.     

元认知监测与算术知识制约小学儿童心算策略运用能力的发展:一年纵向考察

为探究元认知监测与算术知识对儿童心算策略运用能力的影响如何随个体发展而变化，采用计算机任务与纸笔测量的方法，对85名小学三、五年级儿童进行了历时一年的纵向追踪研究。研究发现：（1）两组儿童的元认知监测和算术知识均呈增长趋势，算术知识的增长速度五年级显著快于三年级，且元认知监测增长速度与算术知识增长速度显著相关；（2）两组儿童中，元认知监测与算术知识增长速度更快的个体策略执行反应时与错误率的减少速度也更快；（3）五年级儿童的算术知识在元认知监测影响策略选择发展中起着完全中介作用。     

The role of prior knowledge in error correction for younger and older adults

Previous work has demonstrated that, when given feedback, younger adults are more likely to correct high-confidence errors compared with low-confidence errors, a finding termed the hypercorrection effect. Research examining the hypercorrection effect in both older and younger adults has demonstrated that the relationship between confidence and error correction was stronger for younger adults compared with older adults. However, recent work suggests that error correction is largely related to prior knowledge, while confidence may primarily serve as a proxy for prior knowledge. Prior knowledge generally remains stable or increases with age; thus, the current experiment explored how both confidence and prior knowledge contributed to error correction in younger and older adults. Participants answered general knowledge questions, rated how confident they were that their response was correct, received correct answer feedback, and rated their prior knowledge of the correct response. Overall, confidence was related to error correction for younger adults, but this relationship was much smaller for older adults. However, prior knowledge was strongly related to error correction for both younger and older adults. Confidence alone played little unique role in error correction after controlling for the role of prior knowledge. These data demonstrate that prior knowledge largely predicts error correction and suggests that both older and younger adults can use their prior knowledge to effectively correct errors in memory.     

The transformation of consequential functions in accordance with the relational frames of same and opposite

Although the literature on reinforcement in behavioral psychology is extensive, few studies have examined the derived transformation of reinforcing functions in accordance with equivalence classes, and no published research has yet examined the derived transformation of consequential functions in accordance with nonequivalence relations. In the present study, which consisted of four experiments, the basic preparation was as follows. First, an arbitrary stimulus, B2, was established as a conditioned punisher, using direct stimulus pairing. Following nonarbitrary relational training, designed to establish SAME and OPPOSITE contextual cues, subjects were exposed to arbitrary relational training using these contextual cues to establish A1 as the same as B1 and C1, and as opposite to B2 and C2. Subsequently, C2 (based on its Same relation with B2) functioned as a punisher and C1 (based on its Opposite relation with B2) functioned as a reinforcer in a simultaneous discrimination task. Critically, the C1 stimulus acquired reinforcing functions, based on the derived relation of Opposite, although no such function had actually been established for any member of the network. Furthermore, these effects were observed across ABA reversals in the baseline contingencies.     

Empowerment and threat in response to mass protest shape public support for a social movement and social change: A panel study in the context of the Bersih movement in Malaysia

One path to social change is through sustained collective action. Although such actions often explicitly target the public audience to raise support for a movement's cause, we know little about how the public psychologically responds to protests. To examine this question, a sample of Malaysians was surveyed before and immediately after the occurrence of mass street protests in Malaysia (N = 422) using a two-wave longitudinal design. Analyses revealed that (beyond pre-existing levels of movement identity and support for social change) experiencing empowerment in response to the protests promoted a supportive movement identity and more support for social change after the protests, whereas experiencing threat in response to the protests promoted an oppositional movement identity and less support for social change after the protests. This research suggests that the psychological impact of ongoing protests on the public can determine subsequent public support for the movement and its goals.     

The transformation of consequential functions in accordance with the relational frames of more-than and less-than

Across three experiments, the transformation of consequential functions in accordance with a seven-member relational network (A-B-C-D-E-F-G) was investigated. In this network, the relational rankings ranged from A, ranked the least, to G, ranked the most. In the first phase, contextual cues for more-than and less-than were established by training participants across multiple exemplars to select comparisons containing larger quantities in the presence of the former cue, and fewer quantities in the presence of the latter cue. Participants then were trained in six conditional discriminations (i.e., AD, F>E, and G>F) with the contextual cues as samples and nonsense words as comparisons, and all possible derived relations were tested (e.g., B相似文献   

A within-person theoretical perspective in sales research: outlining recommendations for adoption and consideration of boundary conditions

Abstract

In the sales literature it is standard practice for researchers to collect cross-sectional data from multiple salespeople, and to compare those salespeople on the data obtained. This between-person approach is suitable for research aiming to draw conclusions between salespeople. However, many salesperson processes are dynamic and vary within salespeople over time, requiring datasets with repeated-measures. This article highlights the need to adopt a within-person theoretical perspective in sales research. Critically, the article shows how our present understanding of boundary conditions may change depending on whether a between-person or within-person level of analysis is adopted. Using examples from the sales literature, we show how the practical implications from between-persons research designs do not necessarily generalize to the within-person level. Further, we explain the methodological and analytical considerations that researchers must account for when undertaking within-person research. Furthermore, the article provides decision criteria that help to identify when within-person analysis should be conducted, outlining analysis tools that are capable of correctly estimating within-person effects without bias. Examples of how within-person research can enhance theory within future sales research, and how within-person research may influence management implications are also discussed. Finally, potential remedies to within-person research barriers are given.