The cognitive tests are described in Appendix A along with three estimates of their reliabilities. It is apparent that all of the variables had moderately high reliability as evaluated by internal consistency (i.e., coefficient alpha), alternate forms (i.e., correlation with other test versions), and test-retest (i.e., longitudinal stability coefficient) procedures. More details about the tests and administration procedures, as well as results of confirmatory factor analyses indicating the pattern of relations of variables to ability constructs, have been reported in other publications (Salthouse, 2004 ; 2005 (link); 2007 (link); Salthouse, Pink & Tucker-Drob, 2008 (link); Salthouse & Tucker-Drob, 2008 (link)). The three tests representing each cognitive ability were Matrix Reasoning, Shipley Abstraction, and Letter Sets for reasoning, Spatial Relations, Paper Folding, and Form Boards for spatial visualization, Word Recall, Paired Associates, and Logical Memory for memory, and Digit Symbol, Pattern Comparison, and Letter Comparison for perceptual speed. Four tests were used to assess vocabulary: Vocabulary, Picture Vocabulary, Synonym Vocabulary, and Antonym Vocabulary.