Averaging: An empirical validity criterion for magnitude estimation

Ss judged grayness of neutral value Munsell chips under two response conditions: magnitude estimation and graphic rating. In addition, they judged average grayness of pairs of chips under the same two response modes. The averaging data were evaluated in terms of a simple model for subjective averaging. The graphic rating data fitted the model, but the magnitude estimates showed consistent discrepancy. It was concluded that the Ss were averaging, but that magnitude estimation distorted their judgments.     

The impact of methodological factors on child psychotherapy outcome research: A meta-analysis for researchers

Two recent meta-analyses have generated evidence for child and adolescent psychotherapy effects. However, critics note that such meta-analyses often include studies with methodological shortcomings which might invalidate their results. In the present study, we explored whether the results of the most extensive child/adolescent meta-analysis might have been influenced by such methodological variables, focusing on internal validity and external validity factors. Together, these factors accounted for two-thirds as much variance as the substantive factors (e.g., type of therapy, age) in the original metaanalysis. This suggests that relative to these therapy and child-characteristic variables, methodological factors have a substantial, though smaller, impact on metaanalysis results. In general, increased experimental rigor was related to larger effect sizes; this argues against the hypothesis that methodologically weak studies have led to an overestimate of therapy effects. No significant interactive relations were found between validity factors and predictors of outcome; this suggests that the relations noted in previous metaanalyses between outcome and various variables were notdistorted by the validity factors tested here.The research described here was supported in part by grants from the North Carolina Department of Human Resources, Division of Mental Health, Mental Retardation, and Substance Abuse Services (41626), and from the National Institute of Mental Health (1 RO3 MH38450). The authors gratefully acknowledge the assistance of Todd Morton, who provided reliability coding.     

Preference for familiar humans by rats

Many “higher” animals are commonly assumed to distinguish between individual humans. This belief is based largely on anecdotal reports; in reality, there is little empirical evidence to support human recognition in nonhuman species. We report that laboratory rats consistently chose a familiar human over an unfamiliar human following fourteen and five 10-min exposures and even following a single 10-min exposure. Furthermore, this preference was retained in the absence of additional contact for at least 5 months. These results confirm that laboratory rats can tell individual humans apart, a prerequisite for associating them with hedonic events. Such human-based conditioning, described by Pavlov and by Gantt, Newton, Royer, and Stephens (1966), may have important implications for animal research in a variety of settings.     

“Make things as simple as possible, but no simpler.” A rejoinder to Scruggs and Mastropieri

Scruggs and Mastropieri (Behaviour Research and Therapy, 32, 879–883, 1994) take issue with criticisms of their PND (Percent of Nonoverlapping Data) statistic that we offered in our recent article (Allison & German, Behaviour Research and Therapy, 31, 621–631, 1993), which advocated a regressionbased method for obtaining effect sizes in single-subject studies. They contend that their PND approach has several advantages over our approach because: (1) they believe that, unlike ours, it can take advantage of the small number of observations that are typically available in single-case studies; (2) it is simple to compute; (3) it frees researchers from traditional regression assumptions of normality, homogeneity of variance, and independence of observations and residuals; and (4) it correlates with visual judgements made by experts. As we shall argue, these claims are built upon very questionable assumptions and they are very difficult to substantiate. In addition, we show that the expected value of the PND is so strongly related to sample size as to be rendered meaningless.     

An evaluation of differential prediction of WIAT achievement scores from WISC-III FSIQ across ethnic and gender groups

This study examines differential prediction of WIAT achievement scores based on WISC-III FSIQ in white as compared with African American and Hispanic children, and in females as compared with males. A procedure which allows simultaneous comparisons of slopes and intercepts across groups is employed. The results are consistent with previous research findings in supporting the general absence of bias in predicting achievement from IQ.     

Socialization influences of collegiate female athletes: A tale of two decades

Over the past decade, sport participation opportunities for females have increased dramatically. The purposes of this study were to compare perceptions of encouragement and support from socializing agents for: (a) female collegiate volleyball players competing during the 1979 and 1989 seasons, and (b) female collegiate athletes and female and male nonathletes. Female athletes (n= 345), female nonathletes (n= 128), and male nonathletes (n= 88) completed a questionnaire to assess significant others' influence on sport involvement during childhood, adolescence, and college years. Results indicated that interest and encouragement by parents, older siblings, and friends significantly increased for female athletes over the past 10 years during one or more developmental period. Discriminant analyses revealed that female athletes perceived stronger influences from mother, siblings, friends, and coaches than did male and female nonathletes. These results demonstrate that female athletes received greater social support than their peers a decade earlier, and these influences were significantly different than male and female nonathletes. This study was supported by a grant awarded to the first author by the Center for the Study of Women in Society, University of Oregon, Eugene.     

Sex-selective abortion: a relational approach

A critical application of Ruddick's model of maternal thinking is the best way to grapple with the ethical dilemmas posed by sex-selective abortion which I view as a "moral mistake." Chief among these is the need to be sensitive to local cultural practices in countries where sex-selective abortion is prevalent, while simultaneously developing consistent international standards to deal with the dangers posed by the use of sex-selective abortion to eliminate female fetuses.     

Effects of surface texture on weight perception when lifting objects with a precision grip

In this paper, we show that, when lifting an object using a precision grip with the distal pads of the thumb and index finger at its sides, the perceived weight depends on the object’s surface texture. The smoother the surface texture, the greater the perceived weight. We suggest that a smoother object is judged to be heavier because the grip force, normal to the surface, required to prevent it from slipping is greater. The possibility of there being an influence of surface texture per se is excluded by a second experiment that employed a variant of the precision grip in which the thumb supports the weight of the object from underneath. With the grip oriented in this way, there is no need to match grip force to surface texture and, under these conditions, there is no effect of surface texture on weight perception. In the first two experiments, the test and comparison weights were lifted successively by the same hand. In a third experiment, the effect of surface texture was replicated for sequential lifts made with separate hands. Thus, the effect is not restricted to comparisons made with the same hand.