PLANNING, ENCODING, AND OVERCOMING CONFLICT IN PARTIAL OCCLUSION DRAWING - A NEO-PIAGETIAN MODEL AND AN EXPERIMENTAL-ANALYSIS

A theoretical model of partial occlusion drawing is presented, along w ith three experiments. The experiments used the materials similarity e ffect, i.e., the fact that it is easier to draw partial occlusion when the model objects are quite different from each other (Cox, 1985). Ex periment 1, with 172 5- to 8-year-old subjects, manipulated materials (similar vs dissimilar objects) and viewing condition (unlimited visib ility vs screened after 5 s), to study whether planning or scanning is involved in partial occlusion drawing. The results were consistent wi th the planning hypothesis, but not with the scanning hypothesis. Expe riment 2, with 76 first-graders, explored group-encoding of similar ob jects. Encoding was assessed from verbal descriptions. Layouts were de scribed differently (similar objects yielding group descriptions), and different descriptions were correlated with different drawing strateg ies. We suggest that group-encoding of similar objects creates a drawi ng problem (Experiment 2), and planning is required to solve it (Exper iment 1). A neo-Piagetian model that accounts for drawing performance in terms of incompatible sets of activated schemes and of an activatio n balance between them is presented. Both experimental manipulations a nd differences among subjects in attentional resources are assumed to affect this balance. Three predictions were derived on the conjoint ef fects of object similarity and subject's M capacity and field dependen ce on drawing; Experiment 3, with 79 first-graders, successfully teste d them. (C) 1996 Academic Press, Inc.