This test was designed to measure spatial and perceptual abilities, as well as abstract reasoning. Each question assesses Mary's ability to decode 3D objects and to rotate them, flip them, and manipulate them. In short, this test encourages the brain to mentally construct the pieces of various 3D jigsaw puzzles.

This test does not measure skills within a particular domain, such as numerical or verbal fields, but challenges a person's understanding of physical space. It also tests abstract reasoning capabilities. Abstract reasoning is thought to be indicative of general intelligence (the g factor, short for the general factor, was suggested by Spearman to be common to all intellectual activities). The ability to comprehend spatial problems was coined by Thurstone as the S factor, which he argued was one of the primary mental abilities of the human brain.

As this test does not use words, numbers or concepts that might be biased towards one culture or another, it is relatively culture-fair. Most importantly, it should be noted that specific abilities can always be developed and improved with practice.