Math20SG {SNSequate}

Bivariate score frequencies on two 20-items mathematics tests.

Description

The data set contains the bivariate sample frequencies of number-right scores for two parallel 20-items mathematics tests given to a sample from a national population of examinees. This data has been described and analized by Holland and Thayer (1989); Von Davier et al, (2004).

Usage

data(Math20SG)

Format

A 21x21 matrix containing the bivariate sample frequencies for X (raws) and Y (columns)

References

Holland, P. and Thayer, D. (1989). The kernel method of equating score distributions. (Technical Report No 89-84). Princeton, NJ: Educational Testing Service.

Von Davier, A., Holland, P., and Thayer, D. (2004). The Kernel Method of Test Equating. New York, NY: Springer-Verlag.

Examples

data(Math20SG)
## maybe str(Math20SG) ; ...