Perception and conception in coordination of perspectives.

Conducted 3 experiments, in an attempt to empirically describe the relative development of perceptual and conceptual understanding of projective relationships between objects and to explain a heuristic model of the cognitive processes involved in coordination of perspective tasks. Ss were a total of 330 4-12 yr olds. The results of Exps I and II indicate that the ability to relate perceptually and conceptually left-right and back-front relationships simultaneously emerged between the ages of 41/2 and 53/4 yrs, but by age 53/4 perception was more advanced than conception. On tasks emphasizing perceptual understanding, performance approached asymptote at about age 9, but for tasks emphasizing conceptual understanding, performance was well below asymptote at age 12. In addition, on the latter tasks, the greatest performance increases occurred between the ages of 9 and 11, suggesting that a developmental shift occurs during that age range. The results of all experiments are consistent with a model which identifies "extraction" of spatial relationships from the stimulus array and from the choice stimuli and "comparison" and "matching" of the images derived from extraction as the fundamental processes involved in both the perceptual and conceptual aspects of coordination of perspectives. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of presenting symptom and therapist orientation on treatment outcome. A follow-up study of brief therapy with college students

The dose-response calculation for radio assay of vitamin B12 is carried out using a straight line and a third degree curve to fit the experimentally obtained calibration points. It is shown that high dispersion of the calibration points with respect to the regression line can lead to errors in the calculation of the response. The calculation of the mean dispersion sx with respect to the regression line turns out to be a good criterion for checking the accuracy of the results.