An application of confidence intervals and of maximum likelihood to the estimation of an examinee's ability

A mathematical definition of the theoretical relation between the examinee's actual responses to the test items and his “true ability” is selected. A maximum-likelihood solution is obtained for estimating the examinee's “true ability” from his responses to the items. The standard error of the maximum-likelihood estimate is obtained, its relation to the discriminating power of the test is pointed out, and some generalizations are drawn as to the optimum level of item difficulty. The Neyman-Pearson power function is applied to determine which of two psychological tests is the most powerful for the selection of “successful” examinees.     

Some relations between guttman's principal components of scale analysis and other psychometric theory

Guttman's principal components for the weighting system are the item scoring weights that maximize the generalized Kuder-Richardson reliability coefficient. The principal component for any item is effectively the same as the factor loading of the item divided by the item standard deviation, the factor loadings being obtained from an ordinary factor analysis of the item intercorrelation matrix.     

Patterns of Growth in Adaptive Social Abilities Among Children with Autism Spectrum Disorders

Adaptive social skills were assessed longitudinally at approximately ages 2, 3, 5, 9, and 13 years in a sample of 192 children with a clinical diagnosis of autism (n = 93), PDD-NOS (n = 51), or nonspectrum developmental disabilities (n = 46) at age 2. Growth curve analyses with SAS proc mixed were used to analyze social trajectories over time. Both individual characteristics and environmental resources emerged as key predictors of adaptive social behavior outcome. The gap between children with autism and the other two diagnostic groups widened with time as the social skills of the latter groups improved at a higher rate. However, within diagnostic groups, improvement ranged from minimal to very dramatic. Children with autism most at risk for problems with social adaptive abilities later in life can be identified with considerable accuracy at a very young age so they can be targeted for appropriate early intervention services.     

Neighborhood crime and self-care: risks for aggression and lower academic performance

This longitudinal study evaluated associations among official rates of neighborhood crime, academic performance, and aggression in a sample of 581 children in 1st-3rd grade (6.3-10.6 years old). It was hypothesized that the influence of crime depends on children's unsupervised exposure to the neighborhood context through self-care. Average weekly hours in self-care were trichotomized into low (0-3), moderate (4-9), and high (10-15). Moderate and high amounts of self-care were linked to increased aggression and decreased academic performance for children from high-crime areas (11,230 crimes per 100,000 persons) but not average-crime areas, when the authors controlled for neighborhood, family, and child covariates. In high-crime areas, academic outcomes were more favorable when self-care occurred in combination with after-school program participation.     

Beyond pleasure: emotion activity affects the relationship between attitudes and behavior

The research examined an additional proposed moderator of the attitude-behavior relationship: the activity level of emotions associated with an attitude object. In Experiment 1, participants who self-generated active rather than passive emotions as being associated with gay men displayed greater attitude-behavior consistency in hiring recommendations for a gay job applicant, as did participants who rated active rather than passive experimenter-provided emotions as being associated with gay men. In Experiment 2, participants who were instructed to associate active rather than passive emotions with gay men subsequently displayed greater attitude-behavior consistency in similar hiring recommendations. It is suggested that future research on the affective component of attitudes might benefit from going beyond consideration of whether the associated emotions entail displeasure or pleasure.     

For-profit/nonprofit differences in center-based child care quality: Results from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development

In secondary analyses of National Institute of Child Health and Human Development Study of Early Child Care and Youth Development data, multiple indicators of quality (caregiver wages and turnover; child/staff ratio; caregiver education and professionalism; positive caregiving) were compared between child care centers by sector (for-profit/nonprofit) and subsector (for-profit independent/chain, nonprofit church/nonchurch) at multiple points from infancy through prekindergarten. Nonprofit centers evidenced higher caregiver wages and education at most ages and better quality child/staff ratios, turnover, caregiver professionalism, and positive caregiving for toddlers and preschoolers. Subsector differences in preschool classrooms were more complex. In general, quality was higher in nonprofit non-religiously affiliated centers, intermediate in nonprofit religiously affiliated and for-profit independent centers, and lower in for-profit chains, but differences were not found on every indicator or between every group. Further, for-profit chain status predicted lower quality positive caregiving, controlling for family characteristics, staff, and structural quality, at 54 months, but not 36 months. Results support and extend prior research by controlling for family characteristics. Policy implications regarding supply- and demand-side quality-improvement strategies that address market competition and parent choice across subsectors are discussed.     

Reliability and predictive validity of the WISC-R with native-American Navajos

The reliability and predictive validity of the WISC-R was examined with a sample of 40 Navajo children. Internal consistency reliability estimates of WISC-R subtests as well as composites were found to be low for the Navajo subjects as compared with the reliability coefficients reported in the WISC-R manual. Correlation coefficients between the WISC-R subtests and those of the Wide Range Achievement Test (WRAT) were low. Only the Block Design subtest correlated significantly with the WRAT-Spelling. The predictive validity of the WISC-R IQ scales was similarly found to be very low. Considering the nature and size of sample, cautions in generalizing these findings to other native-American populations are recommended.     

Effects of Directed Thinking on Intentions to Engage in Beneficial Activities: Idea Generation or Mental Simulation?

How might people best persuade themselves to engage in beneficial activities, such as dieting, exercise, and studying? One strategy is to think about actions. Another strategy is to think about reasons. In previous research, students who were directed to think about actions increased their study intentions more than did students who were directed to think about reasons. The present experiment tested whether thinking about actions was effective because of idea generation (coming up with the thoughts) or because of mental simulation (imagining the scenarios). In immediate and delayed measures, directed thinking about actions (but not reasons) proved generally more effective when students focused on mental simulation than when they focused on idea generation. Theoretical and applied implications are discussed.