Abstract
This study describes the origins of the psychological concept of visuo-spatial ability and some philosophical implications. Manifestations of the ability in Geography, Chess, Geometry and Art are examined and classified by reference to Bloom's Taxonomy. The classification is examined for consistency with a number of visuo-spatial tests and definitions are proposed. An experiment at two age levels (8 and 12) is described. This employed three teaching programmes all designed to improve visuo-spatial ability and centred on: 1. Visualisation. 2. Logical Operations 3. A mixture of both in a school curriculum setting. Programme 3 is shown to be superior in some respects at both age levels. Hypotheses linking the definitions of visuo-spatial ability to distinctive psychological processes are rejected after an examination of the experimental findings and visualisation ratings obtained from the older age group. An almost complete absence of sex differences but marked practice effects at both age levels are noted. Evidence concerning the development of visuo-spatial ability in the 8-13 age range is reviewed and hypotheses of development based on a complex model of processes involved in visuo-spatial ability are formulated. The criterion referencing of some test material which is a necessary preliminary to the examination of the hypotheses is described. Evidence is found to support almost all of these.