Grouping Continuous Data in Discrete Intervals: Information Loss and Recovery

Information loss occurs when continuous data are grouped in discrete intervals. After calculating the squared correlation coefficients between continuous data and corresponding grouped data for four population distributions, the effects of population distribution, number of intervals, and interval width on information loss and recover), were examined.     

Why McNemar's Procedure Needs to be Included in the Business Statistics Curriculum

In business research situations it is often of interest to examine the differences in the responses in repeated measurements of the same subjects or from among matched or paired subjects. A simple and useful procedure for comparing differences between proportions in two related samples was devised by McNemar (1947) nearly 60 years ago. Although the technique has enjoyed widespread usage in both behavioral and medical research, it has unfortunately not received proper attention in marketing, advertising, consumer research, public relations, operations management, or organizational behavior endeavors—disciplines wherein it is particularly desirable to evaluate the significance of changes in attitudes, opinions, or beliefs regarding some campaign or strategy. Perhaps the major reason for this obscurity is simply a general lack of awareness as to its value and practical power. The McNemar test is generally not currently being taught to business statistics students. It is the purpose of this article to demonstrate the usefulness and applicability of the McNemar procedure to these aforementioned disciplines so that it may be more appropriately employed as an important confirmatory data analysis tool within the basic business statistics curriculum.     

Potentiation of taste by another taste during compound aversion learning

Two experiments with rat subjects examined whether a saccharin taste could potentiate the conditioning of an aversion to a salty taste when the two stimuli were presented together prior to lithium-induced illness. In Experiment 1, a 0.1% (w/v) saccharin solution potentiated conditioning of a very dilute (0.03%) NaCl solution, but had no demonstrable effect on two stronger NaCl solutions (0.6% and 1.2%). In Experiment 2, the 0.1% saccharin solution again potentiated the 0.03% NaCl target, but weaker and stronger saccharin concentrations (0.033% and 0.3%) did not. The ability of a taste to potentiate a secondtaste is not consistent with theories that assume that potentiation is unique to compounds composed of tastes and other, functionally different, nontaste cues. Potentiation may occur when the target stimulus is weakly conditionable on its own and when the particular combination of target and potentiator facilitates perceptual integration of the compound.     

The effects of phonological transparency on reading derived words

The purpose of this study was to determine whether poor readers have more pronounced problems than average-reading peers reading derived words the base forms of which undergo a phonological shift when a suffix is added (i.e., shift relations as in “natural”), as compared to derived words whose forms are phonologically and orthographically transparent (i.e., stable relations, as in “cultural”). Two computer-based word recognition tasks (Naming and Lexical Decision) were administered to children with reading disability (RD), peers with average reading ability, and adults. Across tasks, there was an effect for transparency (i.e., better performance on stable than shift words) for both child groups and the adults. For the children, a significant interaction was found between group and word type. Specifically, on the naming task, there was an advantage for the stable words, and this was most noteworthy for the children with RD. On the lexical decision task, trade-offs of speed and accuracy were evident for the child reader groups. Performances on the nonwords showed the poor readers to be comparable to the average readers in distinguishing legal and illegal nonwords; further analyses suggested that poor readers carried out deeper processing of derived words than their average reading peers. Additional study is needed to explore the relation of orthographic and phonological processing on poor readers’ memory for and processing of derived words.     

Writing film: making inferences when viewing and reading

This article discusses the ways in which short films on video might be integrated into the English curriculum. I argue that shorts can be used to scaffold writing, and further than this, that students can learn a great deal about narrative form by shuttling between the two media of print and film. The article focuses on a ‘worked example’, being an account of an INSET session using a short film called Father and Daughter.     

Extending Previous cG×I Findings on 5‐HTTLPR's Moderation of Intervention Effects on Adolescent Substance Misuse Initiation

This study addresses replication in candidate gene × environment interaction (cG×E) research by investigating if the key findings from Brody, Beach, Philibert, Chen, and Murry (2009) can be detected using data (N = 1,809) from the PROSPER substance use preventive intervention delivery system. Parallel to Brody et al., this study tested the hypotheses that substance misuse initiation would increase faster from age 11 to age 14 and be higher at age 14 among: (a) 5‐HTTLPR short carrier adolescents versus long homozygotes, (b) control versus intervention adolescents, and (c) 5‐HTTLPR short carriers in the control condition versus all other participants. The hypotheses were generally supported and results were consistent with Brody et al.'s cG×I finding. Results are discussed in light of replication issues in cG×E research and implications for intervention.     

Effect of taste preexposure on taste and odor aversions

Thirsty Sprague-Dawley rats drank flavored water in a wind tunnel prior to lithium-induced toxicosis. Flavors were presented for 5 min; 30 min later a toxin, lithium chloride, was injected. After the rats had recovered, subsequent aversions to the taste and the odor were assessed separately. In Experiment 1, extensive preexposure to the taste component of the flavor attenuated neophobia to the flavor and the subsequent taste aversion. However, the subsequent odor aversion was unaffected. Experiment 2 partially replicated the results of Experiment 1 and showed that, in a situation in which only taste-potentiated odor aversions are usually found, nonpotentiated aversions were evident. Experiment 3 found that, in addition to attenuating taste aversions, taste preexposure enhances the capacity of rats to learn nonpotentiated odor aversions. The results are interpreted with a neural-based model of conditioned flavor aversions.     

Using item response theory to describe the Nonverbal Literacy Assessment (NVLA)

The Nonverbal Literacy Assessment (NVLA) is a literacy assessment designed for students with significant intellectual disabilities. The 218‐item test was initially examined using confirmatory factor analysis. This method showed that the test worked as expected, but the items loaded onto a single factor. This article uses item response theory to investigate the NVLA using Rasch models. First, we reduced the number of items using a unidimensional model, which resulted in high levels of test reliability despite decreasing the number of questions, providing the same information about student abilities in less time. Second, the multidimensional analysis indicated that it is possible to view the NVLA as a test with four dimensions, resulting in more detailed information about student abilities. Finally, we combined these approaches to obtain both specificity and brevity, with a four‐dimensional model using 133 items from the original NVLA.