9 Cognitive variables discussed by Tucker and Lewis (1973)
Tucker and Lewis (1973) introduced a reliability coefficient for ML factor analysis. Their example data set was previously reported by Tucker (1958) and taken from Thurstone and Thurstone (1941). The correlation matrix is a 9 x 9 for 710 subjects and has two correlated factors of ability: Word Fluency and Verbal.
A data frame with 9 observations on the following 9 variables.
Chicago Reading Test: Vocabulary
Chicago Reading Test: Sentences
First and last letters
Four letter words
Same or Opposite
The correlation matrix from Tucker (1958) was used in Tucker and Lewis (1973) for the Tucker-Lewis Index of factoring reliability.
Tucker, Ledyard (1958) An inter-battery method of factor analysis, Psychometrika, 23, 111-136.
L.~Tucker and C.~Lewis. (1973) A reliability coefficient for maximum likelihood factor analysis.
F.~J. Floyd and K.~F. Widaman. (1995) Factor analysis in the development and refinement of clinical
assessment instruments., Psychological Assessment, 7(3):286 – 299.
Dataset imported from https://www.r-project.org.