Thesis
Multidimensional IRT Fit Index SImulation
Simulation code for a study examining the Type 1 error / Power of M2-based global model fit statisics (RMSEA
, SRMSR
, CFI
, and TLI
) for multidimensional IRT models.
For the current results, we are using the 0.08 SRMSR cut-off, 0.05 RMSEA cut-off, and 0.9 for both TLI and CFI.
Simulation Conditions
- Sample Size
- 250,500,750,1000
- # of response options
- 2,3
- # of items
- 18,36
- Level of misspecification (this is for the Power study)
- 10% of items misloaded
- 20% of items misloaded
- 1 correlation misspecified
- 10% of items misloaded & 1 correlation misspecified
- 20% of items misloaded & 1 correlation misspecified
fitsim.R
will run the complete simulation. This will take a very long time and I would recommend the use of a cluster to replicate results.