Factorial dimensions of the Revised Behavior Problem Checklist: Replication and validation within a kindergarten sample

The factor structure of the Revised Behavior Problem Checklist (RBPC) was examined in a large sample of suburban kindergarten children. Teacher-rated dimensions of Conduct Disorder, Attention Problems-Immaturity, Anxiety-Withdrawal, and Psychotic Behavior were closely replicated, and a new factor labeled Unmotivated-Isolated was also revealed. These principal components were consistent across gender and across subsamples of children differing as to risk status for learning failure. Evidence was found for the divergent validity of the externalizing dimensions of Conduct Disorder and Attention Problems-Immaturity with respect to criterion measures of alternative behavior ratings, cognitive functioning, and academic achievement. Parent-rated components of Conduct Disorder, Attention Problems-Immaturity, Hyperactive-Impatient, Tense-Withdrawn, Anxiety, and Passive-Conforming were less clearly validated, and parent-teacher agreement was modest. It was concluded that the RBPC shows promise for the assessment of preschool-aged children and that narrow-band externalizing dimensions of inattentive versus conduct-disordered behavior are reasonably distinct at this age.We would like to express our deep appreciation to Winifred Setrakian, Judy Alien, and Elizabeth Stone of The CHILD Center for their invaluable administrative support.     

Optimal design of parity tests

Researchers often test a null hypothesis of no ability in the populattion (the so-called “parity” hypothesis) using a single, forced-choice question with k alternatives. In this study a result is presented which should help researchers select the number of alternatives that maximizes the statistical power of the parity hypothesis test. Also the conditions under which it is always beneficial to add alternatives to the test are derived. Finally, the derived result is used to compare several popular parity test designs. The results show that the frequently used triangle test is optimal under a very broad range of plausible conditions.     

Pattern redundancy and detection in very short-term memory

A tachistoscopically presented target letter is detected better in a background of redundant items than in nonredundant material. The present experiment extended this finding by showing that detection rate increased systematically across three levels of background letter redundancy. A conclusion based on the earlier findings was that a serial process of letters in memory could not account for the effects of background redundancy on detection accuracy. Contrary to this conclusion, the present analysis showed that detection for semiredundant displays was successfully predicted by two variants of a serial process model. One model assumed that the scan of a letter is faster when the letter is the same as any prior letter scanned in the matrix. The other model assumes that nonredundant letters are processed serially and that redundant letters are processed all at once, i.e., in parallel.     

Choice behavior of rats searching for food

The experiments reported here were designed to determine if several general principles drawn from appetitively motivated discrimination experiments in standard laboratory apparatus might also apply to food-searching behavior under more naturalistic conditions. Food-deprived rats searched for food in an open observation area. Choice behavior after finding food and after not finding food was analyzed. In all cases, not finding food in a possible food location was sufficient to direct subsequent search behavior away from that location for the remainder of the day's test. Finding food had variable effects on subsequent choice behavior, depending on the number of locations that actually contained food and the number of days food was in one location before being shifted to another. The results indicate that the rat's search strategy was influenced by food availability and distribution in ways that are predicted by discrimination learning experiments.     

A developmental study of the effect of familiarity on short-term visual memory

An attempt was made to specify whether previously reported limitations on young children's full-report capacity lay in a smaller amount of available information, in a shorter trace duration of information in visual information storage (VIS), or in poorer coding of information into permanent storage. Five- and 8-year-olds and adults were shown an eight-item array of figures. followed at varying intervals by an indicator signaling the subject to report the figure to which the indicator had pointed. The effects of three levels of familiarity or “labelability” were examined. While no age differences were revealed in amount of information available nor in the trace duration of information in VIS, strong age differences emerged in coding of information into permanent storage. Data on latency to verbal labeling and familiarity suggested that verbal labeling could not account for the age trends. Rather, the differences seemed to lie in the use of organized visual coding and rehearsal strategies by adults and their relative lack of use by children.     

The time required to compare extents in various orientations

In Experiment I, Ss compared the lengths of lines that varied in absolute and relative orientation. Their reaction times showed a constant error pattern of which the familiar horizontal-vertical illusion was a special case, but horizontals were underestimated (relative to other slopes) much more than verticals were overestimate. The effect of difference inorientation was not great, though RT did increase significantly as the difference neared 90 deg. Experiment II was similar except that the lengths of lines were compared withthe widths of bars in a grating. In this case, no consistent pattern of constant error emerged, and there was no suggestion that difference in orientation affected RT.