An updated version of this package has been placed on CRAN. The following are new/fixed in 1.6: 1) The classical() function now computes design-consistent standard errors for a one-stage cluster sample with unbalanced data. 2) The jml() function now uses better starting values to reduce iterations needed to converge. 3) A bug in stringMatch() was resolved. 4) Fixed spelling error in print.summary.cheat function ('cheatering' to 'cheating') 5) Added in mml() function and methods. The mml() function maximizes the marginal likelihood function to obtain estimates of the population parameters (i.e., mean and variance of a normal distribution) treating item responses and item parameters as known. Function currently works for 1-, 2-, and 3PL IRT models. 6) The package vignette is updated to reflect new technical methods and examples. Recommendations, bug fixes, reactions are always welcome. Harold [[alternative HTML version deleted]]