The data set contains raw sample frequencies of number-right scores for two parallel 20-items mathematics tests given to two samples from a national population of examinees. This data has been described and analized by Holland and Thayer (1989); Von Davier et al, (2004) (see also Von Davier, 2011 where other applications using these data set are shown).
A 21x2 matrix containing raw sample frequencies (raws) for two parallel tests (columns)
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.