Ability and Intelligence Tests

Description

Six tests were given to 112 individuals. The covariance matrix is given in this object.

Usage

ability.cov

Details

The tests are described as

general:

a non-verbal measure of general intelligence using Cattell's culture-fair test.

picture:

a picture-completion test

blocks:

block design

maze:

mazes

reading:

reading comprehension

vocab:

vocabulary

Bartholomew gives both covariance and correlation matrices, but these are inconsistent. Neither are in the original paper.

Source

Bartholomew, D. J. (1987). Latent Variable Analysis and Factor Analysis. Griffin.

Bartholomew, D. J. and Knott, M. (1990). Latent Variable Analysis and Factor Analysis. Second Edition, Arnold.

References

Smith, G. A. and Stanley G. (1983). Clocking g: relating intelligence and measures of timed performance. Intelligence, 7, 353–368. doi: 10.1016/0160-2896(83)90010-7.

Examples

require(stats)
(ability.FA <- factanal(factors = 1, covmat = ability.cov))
update(ability.FA, factors = 2)
## The signs of factors and hence the signs of correlations are
## arbitrary with promax rotation.
update(ability.FA, factors = 2, rotation = "promax")