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The Mindful Attention Awareness Scale was developed to measure individual differences in the tendency to be mindful. The current study examined the psychometric properties of the Mindful Attention Awareness Scale in a heterogeneous sample of 565 nonmeditators and 612 meditators using the polytomous Rasch model. The results showed that some items did not function the same way for these two groups. Overall, meditators had higher mean estimates than nonmeditators. The analysis identified a group of items as highly discriminating. Using a different model, Van Dam, Earleywine, and Borders in 2010 identified the same group of items as highly discriminating, and concluded that they were the items with the most information. Multiple pieces of evidence from the Rasch analysis showed that these items discriminate highly because of local dependence, hence do not supply independent information. We discussed how these different conclusions, based on similar findings, result from two very different paradigms in measurement.

Andersen (1995, 2002) proves a theorem relating variances of parameter estimates from samples and subsamples and shows its use as an adjunct to standard statistical analyses. The authors show an application where the theorem is central to the hypothesis tested, namely, whether random guessing to multiple choice items affects their estimates in the Rasch model. Taking random guessing to be a function of the difficulty of an item relative to the proficiency of a person, the authors describe a method for creating a subsample of responses, which is least likely to be affected by guessing. Then using Andersen’s theorem, the authors assess the difference in difficulty estimates between responses from the whole sample and the subsample for each item. To demonstrate the effectiveness of the procedure, data are simulated according to a class of models in which random guessing is a function of the proficiency of a person relative to the difficulty of an item. The procedure is also applied to an empirical data set from Raven’s Advanced Progressive Matrices, with the results indicating that guessing is present in a substantial number of items. It is noted that one especially important application in which estimating the correct relative difficulty of items is required is where the items will form part of an item bank and where on subsequent occasions the items will be administered interactively. In this case, items too difficult for a person are not administered and therefore unlikely to attract random guessing.

Models of modern test theory imply statistical independence among responses, generally referred to as local independence. One violation of local independence occurs when the response to one item governs the response to a subsequent item. Expanding on a formulation of this kind of violation as a process in the dichotomous Rasch model, this article generalizes the dependence process to the case of the unidimensional, polytomous Rasch model. It then shows how the magnitude of this violation can be estimated as a change in the location of thresholds separating adjacent categories in the second item caused by the response dependence on the first. As in the dichotomous model, it is suggested that this index is relatively more tangible in interpretation than other indices of dependence that are either a weight in the interaction term in a model or a correlation coefficient. One function of this method of assessing dependence is likely to be in the development of tests and assessment formats where evidence of the magnitude of dependence of one item on another in a pilot study can be used as part of the evidence in deciding which items will be retained in a final version of a test or which formats might need to be reconstructed. A second function might be to identify the magnitude of response dependence that may then need to be taken into account in some other way, perhaps by applying a model that takes account of the dependence.

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Graffiti is often viewed as a nuisance 'kids' crime, an act of youthful resistance and, as such, it is sometimes given a lower policing prioritisation level than more 'serious' crimes. In this study, the three-year offending histories of 798 graffitists were extracted from the Western Australian Police Information Management System database. To address the study's aim of determining whether agedifferentiated patterns of offending exist among three age-cohorts of offenders (i.e. preteens, adolescents and adults), the number of offences, the number of contacts with police, the type of offences and the rank category of each offence for each of the three age-cohort were calculated. The findings reveal that while 96 graffiti offenders had only one recorded graffiti offence, the majority of graffitists (n 0702) were recidivist offenders involved in multiple crimes. The most prevalent crime among the recidivist preteen and early adolescent cohort of graffiti offenders was burglary; however, the recidivist late-adolescent and adult cohorts of graffiti offenders committed more violent and drug-related crimes.

Andrich, Marais, and Humphry showed formally that Waller's procedure that removes responses to multiple choice (MC) items that are likely to be guessed eliminates the bias in the Rasch model (RM) estimates of difficult items and makes them more difficult. The former did not study any consequences on the person proficiency estimates. This article shows that when the procedure is applied, the more proficient persons who are least likely to guess benefit by a greater amount than the less proficient, who are most likely to guess. This surprising result is explained by appreciating that the more proficient persons answer difficult items correctly at a greater rate than do the less proficient, even when the latter guess some items correctly. As a consequence, increasing the difficulty of the difficult items benefits them more than the less proficient persons. Analyses of a simulated and real example are shown illustratively. To not disadvantage the more proficient persons, it is suggested that Waller's procedure be used when the RM is used to analyze MC items.

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