Comparing models with different varia... PreviousNext
Mplus Discussion > Structural Equation Modeling >
Message/Author
 Sally Czaja posted on Tuesday, June 20, 2006 - 12:03 pm
I would like to compare models (using AIC and AIC weights) in which a 2nd and 3rd predictor is added to a base model that has just 1 predictor. I'm confused on how to specify the simpler models. If the base model is "Y on P;" and the 2nd model is "Y on P C;" (C is a control variable), then the base model has a better (lower) AIC and an AIC weight of 1 (i.e., they're not even close), even though the R-squared is better (higher) in the 2nd model. Should C be in the base model? (if so, how exactly?).

The 3rd model introduces a mediator: "Y on P C M;" "M on P C;". If the comparison model is "Y on P C;", then the simpler model is preferred again. I want to make sure I'm doing this right before I interpret these results.

Thanks.
 Linda K. Muthen posted on Wednesday, June 21, 2006 - 8:05 am
You need to include the full set of variables in each model for the loglikelihood values to be on the same scale.

y ON p c m;
y ON p c m@0;
o ON p c@0 m@0;
Back to top
Add Your Message Here
Post:
Username: Posting Information:
This is a private posting area. Only registered users and moderators may post messages here.
Password:
Options: Enable HTML code in message
Automatically activate URLs in message
Action: