An experimental test of the effects of gender constancy on sex typing

This study provides an experimental test of the hypothesis that level of gender constancy understanding affects children’s sex typing. Preschool-age children (N = 62, mean age = 47 months) were randomly assigned to experimental lessons that taught that biological traits (including gender) are either fixed (pro-constancy condition) or mutable (anti-constancy condition). Posttests revealed that the lessons were effective; children in the pro-constancy condition showed higher gender constancy and appearance–reality distinction scores than did children in the anti-constancy condition. Sex typing did not, however, differ between treatment conditions at immediate and 3-month posttesting.     

An experimental study of the physical and psychological effects of aerobic exercise on schoolchildren

This study compared the physical and psychological effects of running to those of the normal physical education program of activities among 154 fourth, fifth, and sixth graders who were randomly assigned to conditions within a true experimental design. The running program consisted of three 30-min sessions per week for 12 weeks in lieu of attendance in regular physical education classes. Findings showed that although boys tended to run faster than girls overall and that older children run faster than younger children, running-program participants performed better on an 800-m run, had lower pulse rates, and performed better on a test of creativity than did regular physical education participants. Running boys had less body fat, and running girls had more creative involvement in class. No differences were found on 50-m dash performance or perceptual skill. On total behavior, girls were more self-controlled than boys, and self-concept tended to become less positive with increased grade level. Running performance for 800 m persisted for 5 months among boys in the treatment, but not among girls. Running was judged effective for enhancing the cardiorespiratory health and creativity of school children.     

An experimental test of the effects of dieting on bulimic symptoms: the impact of eating episode frequency

Prospective studies suggest dieting increases bulimic symptoms, but experiments suggest that dieting decreases bulimic symptoms. One possible explanation for the conflicting findings is that real world dieting involves less healthy dieting techniques, such as meal skipping, than prescribed diets. We tested whether the manipulation of eating episode frequency during dieting impacted bulimic symptoms. We expected that people on a diet involving fewer eating episodes would exhibit greater increases in bulimic symptoms than people on a diet involving more frequent eating episodes or waitlist controls. Participants on both 6-week diets lost more weight than controls, confirming dieting was manipulated, and showed greater reductions in bulimic symptoms than controls; however, the dieting conditions did not differ on either outcome. Results provide further experimental evidence that dieting does not increase bulimic symptoms, but suggests that eating episode frequency has little impact on this outcome.     

Designing time-limited cyber promotions: effects of time limit and involvement.

This study found that a longer time limit in cyber promotions results in lower time pressure perceptions by consumers and a greater rate of consumers choosing higher-priced items. Furthermore, products with which consumers are more involved entail higher time pressure, lower consumer satisfaction, and a lower share of consumers using the promotion for that product.     

Investigating the relationship between item exposure and test overlap: Item sharing and item pooling

To date, exposure control procedures that are designed to control item exposure and test overlap simultaneously are based on the assumption of item sharing between pairs of examinees. However, examinees may obtain test information from more than one examinee in practice. This larger scope of information sharing needs to be taken into account in refining exposure control procedures. To control item exposure and test overlap among a group of examinees larger than two, the relationship between the two indices needs to be identified first. The purpose of this paper is to analytically derive the relationships between item exposure rate and each of the two forms of test overlap, item sharing and item pooling, for fixed‐length computerized adaptive tests. Item sharing is defined as the number of common items shared by all examinees in a group, while item pooling is the number of overlapping items that an examinee has with a group of examinees. The accuracy of the derived relationships was verified using numerical examples. The relationships derived will lay the foundation for future development of procedures to simultaneously control item exposure and item sharing or item pooling among a group of examinees larger than two.     

Item placement on a personality measure: effects on faking behavior and test measurement properties

Although personality tests are widely used to select applicants for a variety of jobs, there is concern that such measures are fakable. One procedure used to minimize faking has been to disguise the true intent of personality tests by randomizing items such that items measuring similar constructs are dispersed throughout the test. In this study, we examined if item placement does influence the fakability and psychometric properties of a personality measure. Study participants responded to 1 of 2 formats (random vs. grouped items) of a personality test honestly and also under instructions to fake or to behave like an applicant. Results indicate that the grouped item placement format was more fakable for the Neuroticism and Conscientiousness scales. The test with items randomly placed fit the data better within the honest and applicant conditions. These findings demonstrate that the issue of item placement should be seriously considered before administering personality measures because different item presentations may affect the incidence of faking and the psychometric properties of the measure.     

An item/order trade-off explanation of word length and generation effects

The item-order hypothesis suggests that under certain conditions increased item processing can lead to deficits in order processing, and that this produces a dissociation in performance between item and order tasks. The generation effect is one such example. The word length effect is seen as another instance where this trade-off might be observed. The following experiments compare word length and generation effects under serial recall and single item recognition conditions. Short words are better recalled than long words on the serial recall task but long words were better recognised than short words. The results are consistent with the item-order approach and support a novel explanation for the word length effect.     

The experimental study of internal and external conformity on time perception

The purpose of this study is to examine how external conformity affect internal conformity in the conditions in which the degree of discrepancy between majority opinion and physical reality are different. The 106 subjects were divided into eight groups of 2 (male and female) × 2 (high external conformer and low one) × 2 (large discrepancy and small one). We found the effect of interaction between discrepancy condition and external conformity to internal conformity.     

Spoken-word processing in aphasia: effects of item overlap and item repetition

Two studies were carried out to investigate the effects of presentation of primes showing partial (word-initial) or full overlap on processing of spoken target words. The first study investigated whether time compression would interfere with lexical processing so as to elicit aphasic-like performance in non-brain-damaged subjects. The second study was designed to compare effects of item overlap and item repetition in aphasic patients of different diagnostic types. Time compression did not interfere with lexical deactivation for the non-brain-damaged subjects. Furthermore, all aphasic patients showed immediate inhibition of co-activated candidates. These combined results show that deactivation is a fast process. Repetition effects, however, seem to arise only at the longer term in aphasic patients. Importantly, poor performance on diagnostic verbal STM tasks was shown to be related to lexical decision performance in both overlap and repetition conditions, which suggests a common underlying deficit.     

An item factor analysis and item response theory-based revision of the Everyday Discrimination Scale

The Everyday Discrimination Scale (EDS), a widely used measure of daily perceived discrimination, is purported to be unidimensional, to function well among African Americans, and to have adequate construct validity. Two separate studies and data sources were used to examine and cross-validate the psychometric properties of the EDS. In Study 1, an exploratory factor analysis was conducted on a sample of African American law students (N = 589), providing strong evidence of local dependence, or nuisance multidimensionality within the EDS. In Study 2, a separate nationally representative community sample (N = 3,527) was used to model the identified local dependence in an item factor analysis (i.e., bifactor model). Next, item response theory (IRT) calibrations were conducted to obtain item parameters. A five-item, revised-EDS was then tested for gender differential item functioning (in an IRT framework). Based on these analyses, a summed score to IRT-scaled score translation table is provided for the revised-EDS. Our results indicate that the revised-EDS is unidimensional, with minimal differential item functioning, and retains predictive validity consistent with the original scale.