Scoring procedure, performance factors, and magnitude of sex differences in spatial performance.

The purpose of the present study was to demonstrate the influence of procedural factors on the magnitude of sex differences in a test of spatial ability. Two hundred and seven females and 155 males were administered the Mental Rotations Test (MRT) under timed and untimed conditions. Four different scoring procedures were used: total score, ratio of correct responses to the number of items attempted, score out of 24, and score out of 48. Significant sex differences were obtained in the timed condition but not in the untimed condition. Results also revealed that the magnitude of sex differences was reduced when a ratio score was used. Analysis of the pattern of responses provided insights into the causes of sex differences on the MRT. Results are interpreted in terms of their implications for research on sex differences in spatial ability.