The relative error magnitude in three measures of change

Formulas for the standard error of measurement of three measures of change—simple difference scores, residualized difference scores, and the measure introduced by Tucker, Damarin, and Messick—are derived. Equating these formulas by pairs yields additional explicit formulas which provide a practical guide for determining the relative error of the three measures in any pretest-posttest design. The functional relationship between the standard error of measurement and the correlation between pretest and posttest observed scores remains essentially the same for each of the three measures despite variations in other test parameters (reliability coefficients, standard deviations), even when pretest and posttest errors of measurement are correlated.     

Cultural differences on WISC-R verbal items

The item difficulty patterns of four groups of nonreferred, average children— Anglos, Blacks, Chicanos and Bermudians—were compared on each of the verbal subtests of the Wechsler Intelligence Scale for Children-Revised. The analysis was done for $\text{7}\text{1}\text{2}$ years old and $\text{10}\text{1}\text{2}$ year olds separately. Although this procedure identified a small number of items differentially difficult for one group of children or another, the item difficulty curves for the four groups were remarkably parallel, considering the differences in the children's cultures.     

Enhancing the social skills of an unpopular girl: A social learning intervention

The use of a social learning approach to reduce the unpopularity of an 11-year-old girl, Rene, at a summer camp was studied. Two social skill deficiencies were suggested to be the cause of Rene's unpopularity by her bunk house counselors: her lack of contact with bunkhouse members during free choice times, and her negative, interfering conversational style. A multiple baseline design was used by the counselors to successively implement reinforcement contingencies on each class of social skill. Substantial improvements in performance were noted concurrent with the application of each contingency. These outcomes were maintained after reinforcement contingencies were withdrawn. Sociometric ratings of Rene's popularity by her bunkhouse mates improved after intervention. These outcomes are discussed from a social learning perspective.     

Further evidence for Coren and Hakstian’s “Methodological implications of interaural correlation: Count heads not ears” and an alternative correction formula

Coren and Hakstian (1990) identified a serious methodological problem that arises in auditory research because of interaural correlation. When measures from both ears of the subjects are pooled together in an experimental design that assumes independence of measures, there can be spuriously high apparent statistical significance. The present paper provides further evidence in support of Coren and Hakstian’s argument and also derives a formula that effectively corrects inflated test statistics resulting from interaural correlation. This formula is a special case of a more general one that applies in many other experimental contexts in which nonindependence of measures is a problem. We found that statistical tests based on our formula have somewhat greater power to detect differences than the kind of correction method advocated by Coren and Hakstian.     

Sex factors in children's observational learning of value judgments of toys

Sex Roles - Preschool children observed the play of a male or female model with a nonpreferred toy. The model's play incorporated a masculine or feminine storylike sequence of actions or was...     

Facilitation of both “same” and “different” judgments of letter strings by familiarity of letter sequence

Three experiments employing simultaneous matching were performed to extend recent findings that three kinds of familiarity—familiarity of letter sequences, familiarity of display configuration, and familiarity of letter orientation—facilitate the matching of letter strings for “same” responses and sometimes for “different” responses. It was found that letter sequence familiarity facilitated “same” responses even when the letter strings were in an unfamiliar orientation or configuration and also facilitated “different” responses whenever the task required that a substantial portion of the display be processed before a response could be initiated. A three-stage model of the simultaneous letter-string matching task was developed. This model, which assumes that the same processes account for both “same” and “different” responses, was consistent with findings obtained when there were small differences between string pairs. Discrepant findings obtained when there were large differences between string pairs may have been produced by the premature initiation of responses.     

Concept attainment, transfer, and retention through observation and rule-provision

The effects of observing a model and of providing a response rule on the learning, transfer, and retention of a dial-reading, numerical concept were studied in 144 third graders. Different Es conducted the immediate learning procedures versus the measurements of retention. No extrinsic reinforcers were promised or dispensed. The children profited both from modeling and from rule-provision, with the strongest learning, transfer, and retention displayed by the group that watched the model and also received the rule summary. Sequence of presenting the sets of retention stimuli (including a series of novel generalization items not previously encountered) did not influence the strength of concept retention 6 weeks after training.     

Multivariate discriminant analysis of EEG power spectra in acute schizophrenic patients and healthy probands

The electroencephalogram (EEG) during information processing is influenced by specific changes in brain electrical activity. Based on the theory of a disturbed information processing in schizophrenics we analysed auditory stimulus induced EEG changes by Fast Fourier Transformation. The most important of the significant stimulation dependent EEG power changes were measured in the 0.5-3.5 Hz and 10-13.5 Hz frequency bands in the left parietal lead. In a multivariate analysis the separation of the subjects examined into acute schizophrenics and normals was incorrect in only 21% of the cases (resubstitution rate): using the pi-method an error of 31% was estimated.     

Water and NaCl intake after furosemide treatment in sheep (Ovis aires)

Intravenous infusion of the natriuretic drug furosemide in sheep led to the excretion of large quantitites of hypotonic urine. The sheep consumed more water than was needed simply to restore osmotic equilibrium. The stimulus for the additional intake was presumably hypovolemia resulting from the loss of sodium in urine. Despite the natriuresis, in only 2 of 15 experiments did sheep drink significant amounts of .5 M NaCl solution during the first 10 hr after the onset of furosemide treatment, and hemoconcentration and arterial hypotension were evident during this time. By 24 hr, however, the saline consumption in all but three experiments had increased and compensated adequately (together with the water intakes) for the furosemide-induced loss of sodium-rich fluid in urine. These results provide evidence that following acute hypovolemia in sheep, as in rats, the onset of sodium appetite is delayed relative to the appearance of thirst.