resp
A matrix of responses: persons as rows, items
as columns, entries are either 0 or 1, no missing data
ip
Item parameters: a matrix with one row per
item, and three columns: [,1] item discrimination
$a$, [,2] item difficulty $b$, and [,3] asymptote
$c$.
theta
A measure of ability, typically produced
with mlebme, wle etc. If missing, ML
estimates will be computed automatically.