Item difficulty and discrimination {Rfast2}

Item difficulty and discrimination

Description

Item difficulty and discrimination.

Usage

diffic(x)

discrim(x, frac = 1/3)

Arguments

x

A numerical matrix with 0s (wrong answer) and 1s (correct answer).

frac

A number between 0 and 1 used to calculate the difficulty of each question.

Details

The difficulty and the discrimination of each question (item) are calculated.

Value

A vector with the item difficulties or item discriminations.

Author(s)

Michail Tsagris.

R implementation and documentation: Michail Tsagris [e-mail].

References

Kaplan E. L. and Meier P. (1958). Nonparametric estimation from incomplete observations. Journal of the American Statistical Association, 53(282): 457-481.

See Also

Quantile, colmeansvars

Examples

x <- matrix(rbinom(100 * 10, 1, 0.7), ncol = 10)
diffic(x)
discrim(x)