Thom Baguley

From alpha to omega: a practical solution to the pervasive problem of internal consistency estimation

Coefficient alpha is the most popular measure of reliability (and certainly of internal consistency reliability) reported in psychological research. This is noteworthy given the numerous deficiencies of coefficient alpha documented in the psychometric literature. This mismatch between theory and practice appears to arise partly because users of psychological scales are unfamiliar with the psychometric literature on coefficient alpha and partly because alternatives to alpha are not widely known. We present a brief review of the psychometric literature on coefficient alpha, followed by a practical alternative in the form of coefficient omega. To facilitate the shift from alpha to omega, we also present a brief guide to the calculation of point and interval estimates of omega using a free, open source software environment.

Standardized or simple effect size: What should be reported?

It is regarded as best practice for psychologists to report effect size when disseminating quantitative research findings. Reporting of effect size in the psychological literature is patchy - though this may be changing - and when reported it is far from clear that appropriate effect size statistics are employed. This paper considers the practice of reporting point estimates of standardized effect size and explores factors such as reliability, range restriction and differences in design that distort standardized effect size unless suitable corrections are employed. For most purposes simple (unstandardized) effect size is more robust and versatile than standardized effect size. Guidelines for deciding what effect size metric to use and how to report it are outlined. Foremost among these are: (i) a preference for simple effect size over standardized effect size, and (ii) the use of confidence intervals to indicate a plausible range of values the effect might take. Deciding on the appropriate effect size statistic to report always requires careful thought and should be influenced by the goals of the researcher, the context of the research and the potential needs of readers.

Calculating and graphing within-subject confidence intervals for ANOVA

The psychological and statistical literature contains several proposals for calculating and plotting confidence intervals (CIs) for within-subjects (repeated measures) ANOVA designs. A key distinction is between intervals supporting inference about patterns of means (and differences between pairs of means, in particular) and those supporting inferences about individual means. In this report, it is argued that CIs for the former are best accomplished by adapting intervals proposed by Cousineau (Tutorials in Quantitative Methods for Psychology, 1, 42–45, 2005) and Morey (Tutorials in Quantitative Methods for Psychology, 4, 61–64, 2008) so that nonoverlapping CIs for individual means correspond to a confidence for their difference that does not include zero. CIs for the latter can be accomplished by fitting a multilevel model. In situations in which both types of inference are of interest, the use of a two-tiered CI is recommended. Free, open-source, cross-platform software for such interval estimates and plots (and for some common alternatives) is provided in the form of R functions for one-way within-subjects and two-way mixed ANOVA designs. These functions provide an easy-to-use solution to the difficult problem of calculating and displaying within-subjects CIs.

Resolving semantically induced tip-of-the-tongue states for proper nouns

Three experiments are reported in which tip-of-the-tongue states (TOTSs) were induced in subjects by reading them pieces of item-specific information. In Experiments 1 and 2, subjects attempted toname famous people. These experiments showed that, in a TOTS, seeing a picture of the faceof the target person did not facilitate naming, whereas the initials of the person’s name did. In Experiment 3, a similar result was obtained with a landmark-naming task. The results of the experiments are discussed with reference to current models of memory structure and name retrieval.

Online gaming addiction: Classification, prediction and associated risk factors

Massively multiplayer online role-playing games (MMORPGs) have gained increased popularity over the last decade. Despite the many positives of gaming, alleged problems relating to MMORPG playing have emerged, more specifically in relation to addiction to MMORPGs among a small minority of players. This study set out to establish the prevalence of MMORPG addiction using validated addiction criteria. Factors relating to online gaming were examined to establish whether they were linked to MMORPG addiction. A self-selected sample of 1420 gamers ranging in age from 12 years to 62 years (mean age 23 years) completed an online questionnaire. The results showed that 44.5% of gamers were classified as addicted according to the polythetic format and 3.6% according to the monothetic format. Ordered logistic regression analysis showed that the variable years of gaming, total time spent playing online per week and employment status can have a major impact on the probability of MMORPG addiction. The implications of these findings for the assessment of MMORPG addiction are discussed.

Potential early-life predictors of dietary behaviour in adulthood: a retrospective study

OBJECTIVE:Unnecessary dietary restraint (ie in the absence of a need to lose weight) and chronic overeating are both very unhealthy activities. As a precursor to a more involved longitudinal study, we sought to identify potential early-life predictors that merit scrutiny in this context.DESIGN:Four retrospective questionnaire studies were conducted (Study 1, N=242; Study 2, N=297; Study 3, N=175; Study 4, N=261). Female participants (18–30 y) completed measures of current dietary restraint and overeating. They also recalled experiences between 5 and 10 years of age. All were staff or students at Loughborough University (UK).RESULTS:After considering obvious sources of systematic bias, we report evidence that (i) dietary restraint is related to memories of maternal weight and dietary behaviour, and (ii) overeating and meal-size selection are both associated with memories of receiving a high-energy diet.CONCLUSION:The role of maternal factors in dietary restraint is consistent with previous research exploring the early onset of this behaviour. However, the relationship between childhood diet and overeating has not been suggested elsewhere. This is particularly important because it suggests a previously unreported correspondence between childhood experience and behaviours associated with obesity in adulthood.

Prior approval: the growth of Bayesian methods in psychology.

Within the last few years, Bayesian methods of data analysis in psychology have proliferated. In this paper, we briefly review the history or the Bayesian approach to statistics, and consider the implications that Bayesian methods have for the theory and practice of data analysis in psychology.

Long-term memory for spatial and temporal mental models includes construction processes and model structure.

There is a strong case that people construct and manipulate mental models in working memory but relatively little evidence that mental models are preserved in long-term memory. Instead people may remember an episodic construction trace: a record of the operations used to construct a mental model (Payne, 1993). Experiment 1 investigated memory for determinate spatial descriptions (which describe a single configuration of objects) and indeterminate spatial descriptions (which describe two equally plausible configurations). Recognition performance was impaired when the overlap between the episodic construction trace of a description at learning and at test was disrupted by reordering the sentences within a description. Participants were better at remembering the gist of determinate descriptions than that of indeterminate descriptions. For indeterminate descriptions, provided differences in gist recognition were controlled, participants showed better memory for the original description. Experiment 2 showed a similar pattern of results with temporal descriptions. A third experiment manipulated the similarity between foils in the recognition test and the original descriptions to provide further evidence for both episodic construction trace and remembered mental models. In combination, these results favour a hybrid account of memory for mental models, which includes information about both construction processes and model structure.

Concordant Cues in Faces and Voices: Testing the Backup Signal Hypothesis

Information from faces and voices combines to provide multimodal signals about a person. Faces and voices may offer redundant, overlapping (backup signals), or complementary information (multiple messages). This article reports two experiments which investigated the extent to which faces and voices deliver concordant information about dimensions of fitness and quality. In Experiment 1, participants rated faces and voices on scales for masculinity/femininity, age, health, height, and weight. The results showed that people make similar judgments from faces and voices, with particularly strong correlations for masculinity/femininity, health, and height. If, as these results suggest, faces and voices constitute backup signals for various dimensions, it is hypothetically possible that people would be able to accurately match novel faces and voices for identity. However, previous investigations into novel face–voice matching offer contradictory results. In Experiment 2, participants saw a face and heard a voice and were required to decide whether the face and voice belonged to the same person. Matching accuracy was significantly above chance level, suggesting that judgments made independently from faces and voices are sufficiently similar that people can match the two. Both sets of results were analyzed using multilevel modeling and are interpreted as being consistent with the backup signal hypothesis.

Balancing collaboration and privacy in academic workspaces

Purpose – The purpose of this paper is to evaluate the effectiveness of two different academic office environments in supporting collaboration and privacy.Design/methodology/approach – The approach takes the form of case studies involving post‐occupancy questionnaire surveys of academic occupants.Findings – The combi‐office design was found to be associated with higher levels of occupant satisfaction than the open‐plan office design, with respect to support for collaboration and privacy.Research limitations/implications – The findings highlight the importance of understanding user requirements and the role of office space as a cognitive resource.Practical implications – Designers should consider the default location of occupants when designing academic and other creative workspaces.Social implications – Academic creativity and innovation are seen to be important for society. However, there needs to be a better understanding of how to support this through workspace design.Originality/value – This study con...