Not used. Forces remaining arguments to be specified by name.
qwidth
positive width of quadrature in Z units
qpoints
number of quadrature points
.twotier
whether to enable the two-tier optimization
References
Li, Z., & Cai, L. (2012, July). Summed score likelihood based indices for testing
latent variable distribution fit in Item Response Theory. Paper presented at
the annual International Meeting of the Psychometric Society, Lincoln,
NE. Retrieved from http://www.cse.ucla.edu/downloads/files/SD2-final-4.pdf