tcc function

computes a test characteristic curve (tcc)

computes a test characteristic curve (tcc) from input item parameters

tcc(a, cb, theta, model = "GRM")

Arguments

• a: a vector of slope parameters
• cb: a matrix of category boundary/threshold parameters
• theta: a grid of theta values
• model: IRT model, either "GRM" or "GPCM"

Details

Either the graded response model (GRM) or the generalized partial credit model (GPCM) can be specified. The lowest response/score for each item is coded as 0 not 1.

Returns

Retruns a vector of tcc values over a theta grid

Author(s)

Seung W. Choi choi.phd@gmail.com

See Also

probgrm, probgpcm

Examples

## Not run: tcc(a,cb,theta,model="GRM")
## Not run: tcc(a,cb,theta,model="GPCM")