- How can I interpret it? (when the intraclass correlation coefficient is 5.2%,sigma-square 0.9554 (0.028),tau 0.0522(.013))
- What should I do next?
My main goal is to compare a multilevel item response theory(MLIRT) model with traditional multilevel model(ML) using TIMSS data. For MLIRT I use mlirt package under R developed by Fox (2003) and for ML I use HLM software. Because ability estimates used
in MLIRT are on a scale with mean of 0 and SD of 1, I transformed plausible values to a scale with mean of 0 and SD of 1 then the estimates could be comparable. Sample size is 2362 students nested within 116 schools.
With "non significant random intercept" I meant fixed part of model.The variance component of level-2 (Tau) is significant based on the
chi-square test provided in the output by HLM and also fiexd part. But random intercept (Gamma00 or G00) using MLIRT is not significant (G00=-0.0059 (0.0298)).FYI, model specifications and data are the same across methods.