Tucker R Documentation

## 9 Cognitive variables discussed by Tucker and Lewis (1973)

### Description

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.

### Usage

data(Tucker)

### Format

A data frame with 9 observations on the following 9 variables.

t42

Prefixes

t54

Suffixes

t45

t46

t23

First and last letters

t24

First letters

t27

Four letter words

t10

Completion

t51

Same or Opposite

### Details

The correlation matrix from Tucker (1958) was used in Tucker and Lewis (1973) for the Tucker-Lewis Index of factoring reliability.

### Source

Tucker, Ledyard (1958) An inter-battery method of factor analysis, Psychometrika, 23, 111-136.

### References

L.~Tucker and C.~Lewis. (1973) A reliability coefficient for maximum likelihood factor analysis. Psychometrika, 38(1):1–10.

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.

### Examples

data(Tucker)
fa(Tucker,2,n.obs=710)
omega(Tucker,2)