New in 0.2.2 Fixed the name of the vignette in the vignette index entry! New in 0.2.1 Nothing, really, except that I had to provide new links to the ICL files as a result of Dropbox's new policy on shared files. God bless Brad's beautiful soul, 15 years dead and still helping us. New in 0.2.0 * Added functions to estimate and plot the interaction model * Added erf, a function to plot the empirical item response function * Added ssm, a function to produce IRF in the sum score metric * Added ifp, a function to plot IRF with error bounds. * Small improvements in the tia function * Links to download Brad Hanson's ICL program (see the package help page) CHANGES IN irtoys VERSION 0.1.7 NEW FEATURES o new function, tet(), to calculate, quickly, an approximate matrix of tetrachoric correlations. BUG FIXES o fixed a bug in function wle() which affected the variance of Warm's weighted estimate of ability in the case of the 3PL model only.