Spatial visualization ability

Spatial Visualization Ability refers to the ability to mentally manipulate 2-dimensional and 3-dimensional figures. It is typically measured with simple cognitive tests and is predictive of user performance with some kinds of user interfaces.

Measurement
The cognitive tests used to measure Spatial Visualization Ability include mental rotation tasks and cognitive tests like the VZ-1 (Form Board), VZ-2 (Paper Folding), and VZ-3 (Surface Development) tests from the Kit of Factor-Reference cognitive tests produced by the College Board. Though the descriptions of Spatial Visualization and mental rotation sound similar, mental rotation is a particular task that can be accomplished using spatial visualization.

The Form Board test involves giving participants a shape and a set of smaller shapes. They are then instructed to determine which combination of small shapes will fill the larger shape completely without overlapping.

The Paper Folding test involves showing participants a sequence of folds in a piece of paper, through which a set of holes is then punched. The participants must choose which of a set of unfolded papers with holes corresponds to the one they have just seen.

The Surface Development test involves giving participants a flat shape with numbered sides and a three-dimensional shape with lettered sides and asking the participants to indicate which numbered side corresponds to which lettered side.

Sex Differences
Men do slightly better than women on measures of spatial visualization ability, though the effect size is small. This domain is one of the few where clear sex differences in cognition appear. It has also been found that spatial ability correlates with verbal ability in women but not in men, suggesting that women may use different strategies for spatial visualization tasks than men do.

Age Differences
Older adults tend to perform worse on measures of spatial visualization ability than younger adults, and this effect seems to occur even among people who use spatial visualization frequently on the job, such as architects (though architects still perform better on the measures than non-architects of the same age). It is, however, possible that the types of spatial visualization used by architects are not measured accurately by the tests.

Human-Computer Interaction
In Human-Computer Interaction, differences in spatial visualization ability lead to certain users performing more efficiently than others at information search and information retrieval. This performance difference does not mean that users with low spatial visualization ability cannot find information, but that they tend to be slower at doing so. Spatial visualization ability is also not completely static; it can be improved with practice. However, since the onus in the design of computer systems is on the designer to provide systems that can be used by the majority of users or customers, compensating for low spatial abilities in the target populations is generally considered to be a good idea.

Interventions that help out those with low spatial abilities on the WWW include spatial organizers like site maps and site structure previews, which can improve the performance of people with lower spatial visualization ability while not hurting those with higher spatial visualization ability. Improving the interface apparency by reducing the number of hidden dependencies between actions also improves the performance of low Spatial Visualization individuals while increasing the performance of high Spatial Visualization individuals to a slightly lesser degree.

History
Spatial visualization ability itself is not new. The construct of spatial visualization ability was first identified as a separate thing from general intelligence in the 20th Century, and its implications for computer system design were identified in the 1980's.

In 1987, Kim Vicente and colleagues ran a battery of cognitive tests on a set of participants and then determined which cognitive abilities correlated with performance on a computerized information search task. They found that the only significant predictors of performance were vocabulary and spatial visualization ability, and that those with high spatial visualization ability were twice as fast to perform the task as those with lower levels of spatial visualization ability.