EFFECT OF INSTRUCTIONS, ENVIRONMENT, AND TYPE OF TEST OBJECT ON MATCHED SIZE

Objective instructions in outdoor settings consistently produced the highest magnitude size matches when compared with apparent and retinal instructions and were veridical when the test object was familiar and the environment contained conspicuous depth cues. Overconstancy is favored by the use of unfamiliar test objects and an open field environment. The magnitude of size matches decreases with distance under apparent and retinal instructions, but remains constant under objective instructions. The effect of reduction is much less than previously reported in the literature for experiments conducted in an indoor environment. It should be emphasized that there is no unique function relating matched size to distance, but rather a family of functions whose parameters are particularly sensitive to variables such as instructions, the nature of the test object, and the environment. (19 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.