What colour is a shadow? Black, grey, or some other colour? This article describes how to use a digital camera to test the hypothesis that a shadow under a clear blue sky has a blue tint. A white sheet of A4 paper was photographed in full sunlight and in shadow under a clear blue sky. The images were analysed using a shareware program called…

Two different traditions of response-time (RT) modeling are reviewed: the tradition of distinct models for RTs and responses, and the tradition of model integration in which RTs are incorporated in response models or the other way around. Several conceptual issues underlying both traditions are made explicit and analyzed for their consequences. We…

In this study, the effectiveness of detection of differential item functioning (DIF) and testlet DIF using SIBTEST and Poly-SIBTEST were examined in tests composed of testlets. An example using data from a reading comprehension test showed that results from SIBTEST and Poly-SIBTEST were not completely consistent in the detection of DIF and testlet…

Almost everything is now available online. What is good about this is that in most circumstances, libraries are no longer limited to serving users within just physical spaces. This proves to be a wonderful benefit for users, but sometimes it does not always work out as expected. Those familiar with setting up electronic resources know the…

Traditional methods for examining differential item functioning (DIF) in polytomously scored test items yield a single item-level index of DIF and thus provide no information concerning which score levels are implicated in the DIF effect. To address this limitation of DIF methodology, the framework of differential step functioning (DSF) has…

If a person were to ask an educator to identify the two most important attributes of an education test, the response most certainly would be "validity and reliability." These two tightly wedded concepts have become icons in the field of education assessment. As far as validity is concerned, the term doesn't refer to the accuracy of a test. Rather,…

Background: Genetic disorders occasionally provide the means to uncover potential mechanisms linking gene expression and physical or cognitive characteristics or behaviour. Prader-Willi syndrome (PWS) is one such genetic disorder in which differences between the two main genetic subtypes have been documented (e.g. higher verbal IQ in one vs.…

Using data from the Project on Human Development in Chicago Neighborhoods (PHDCN), we identified a significant inverse association between the variety of youth organizations available at the neighborhood level and adolescents' exposure to community violence. We examined two non-competing explanations for this finding. First, at the individual…

Social skill excesses and deficits have garnered considerable attention from researchers and clinicians over the last three decades. This trend is undoubtedly due to the central role these problems play in psychopathology and the general adjustment of children of all ages. Not surprisingly, these concerns and attention to such problems have also…

This paper presents an empirical micro-simulation model of the teaching and the testing process in the classroom (Programs and sample data are available--the actual names of pupils have been hidden). It is a non-econometric micro-simulation model describing informational behaviors of the pupils, based on the observation of the pupils'…

Camouflage is a prevalent feature of the natural world and as such has a ready appeal to students; however, it is a difficult subject to study using real predators and prey. This paper focuses how one fundamental type of camouflage, disruptive colouration (bold markings that break up the outline of the organism), can be tested using paper…

Divergent thinking is an integral process in creativity. Openness to experience is a personality trait that relates to divergent thinking and, therefore, is hypothesized to be related to creative performance among the students. The effects of openness to experience are likely to be partially mediated by an individual's attitude toward divergent…

The pressing need for English oral communication skills in multifarious contexts today is compelling impetus behind the large number of studies done on oral proficiency interviewing. Moreover, given the recently articulated concerns with the fairness and social dimension of such interviews, parallel concerns have been raised as to how most fairly…

In the Fall of 2010, the Bureau of Indian Education (BIE) approached Northwest Evaluation Association (NWEA) to commission a report of system-wide performance for their first full school year of testing as part of the BIE-NWEA Project. Even with only a single year of testing data, some patterns were identified and they are listed in this report.…

As an extension of the effort devoted to updating the questionnaires for TIMSS and PIRLS 2011, this dissertation explored a new reporting strategy for contextual questionnaire data. The study investigated the feasibility of constructing "global indicators" from a large number of diverse background variables, which could provide policy…