ability.cov             package:datasets             R Documentation

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.

Examples:

     require(stats)
     (ability.FA <- factanal(factors = 1, covmat=ability.cov))
     update(ability.FA, factors=2)
     update(ability.FA, factors=2, rotation="promax")

