lsat {SMIR}R Documentation

LSAT

Description

The original dataset consists of responses from 1,000 subjects to five dichotomous items from section 6 of the LSAT exam. The version here is presented as frequencies of unique patterns of responses. The data is from Bock and Lieberman 1970.

Usage

data(lsat)

Format

A data frame with 32 observations on the following 7 variables. The variable wt7 represents the number with each pattern.

y1
a numeric vector
y2
a numeric vector
y3
a numeric vector
y4
a numeric vector
y5
a numeric vector
wt6
a numeric vector
wt7
a numeric vector

Note

See p.547 in SMIR

Source

Bock, R. and Leiberman, M. (1970), "Fitting a response model for a $n$ dichotomously scored items." Psychometrika, 35, 179–197.

References

Bock, R. D. and Aitkin, M. (1981). "Marginal maximum likelihood estimation of item parameters: An application of an EM algorithm." Pyschometrika, 46, 443–459.

Examples

data(lsat)

[Package SMIR version 0.02 Index]