tsc {irtoys} | R Documentation |
Computes the IRT true scores (test response function at the estimated ability) and an estimate of their standard error via the delte theorem, treating item parameters as known).
tsc(ip, theta)
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 |
An object containing ability estimates, as output by function mlebme or eap |
A matrix with the true scores in column 1, and their standard errors of measurement (SEM) in column 2
Ivailo Partchev
data(Scored) p.2pl <- est(Scored, model="2PL", engine="ltm") th <- mlebme(resp=Scored, ip=p.2pl) tsc(p.2pl, th)