read.ip.bilog {irtoys}

Read in parameter estimates

Description

From BILOG output, read in estimates of item parameters. Invoked automatically when the model is estimated via irtoys. If that is not the case, file must be a file produced with the >SAVE PARm file; command in BILOG.

Usage

read.ip.bilog(file)

Arguments

file

File name

Value

A list with three elements, est, se, vcm for the parameter estimates, their standard errors, and the variance-covariance matrix per item. The first two are matrices with one row per item, and three columns: [,1] item discrimination a, [,2] item difficulty b, and [,3] asymptote c. For the 1PL and 2PL models, all asymptotes are equal to 0; for the 1PL, the discriminations are all equal but not necessarily equal to 1.

Author(s)

Ivailo Partchev