Although it is sometimes claimed that Raven's Matrices provide an almost pure measure of g, there is evidence that the easier items in the Standard Progressive Matrices and in Set I of the Advanced Matrices measure a perceptual or Gestalt factor distinct from the more analytic items in the rest of the tests. There is also, however, both factor…

The impact of general control processing and working memory capacity on a measure of abstract intelligence was examined with 577 military recruits. A new multicomponent latent trait model for covert response was applied to item response data for matrix problems. General control processing has a stronger impact. (SLD)

The stability of psychometric "g," the general factor of intelligence, is investigated in simulated correlation matrices and in typical empirical data from a large battery of mental tests. "G" is robust and almost invariant across methods of analysis. A reasonable strategy for estimating "g" is suggested. (SLD)