/Thesis

Multidimensional IRT Fit Index SImulation

Primary LanguageR

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.