Pictorial depth perception: Tasks levels imposed by testing instruments

Attempts to devise verbal and non-verbal instruments for measuring pictorial depth perception that are different from Hudson's (1960) have resulted in different perceptual demands. Whereas this was recognized by the constructors of non-verbal tests, it was not by those who changed Hudson's question “Which is nearer to the man…?” to “Which is/looks nearer/farther to you… ?”. While the latter question tests simple perception (or interpretation of cues) of pictorial depth, the former tests comprehension of complex pictorial space relations arising from the depth perceived. A verbal instrument that had been devised for testing simple pictorial depth interpretation, equivalent to Jahoda and McGurk's (1974) non-verbal instrument, was tested on Grade 3 Shona children against the hypothesis that the terms “nearer” and “farther” have different lexical markings likely to affect subject's responses. No support was found for the hypothesis, but Opolot's (1976) Grade 3 findings were able to be explained.