Compute surrogate theta values as the set of normalized first
principal component scores.
Usage
get_surrogates(dat)
Arguments
dat
Matrix of binary item responses.
Value
Vector of surrogate theta values.
Details
Compute surrogate theta values as the
normalized first principal component scores.
References
Liang, L., & Browne, M. W. (2015). A quasi-parametric method for
fitting flexible item response functions. Journal of Educational and
Behavioral Statistics, 40, 5--34. 10.3102/1076998614556816