Kevin McGrew posted on Wednesday, February 16, 2011 - 2:30 pm
I have successfully saved factor scores for a three indicator single factor model, as well as other factor models The factor scores always have the excepted mean of zero, and an SD that varies by factor. For example, factor 1 scores have mean =0 and SD=6.6.
I now want to transform these to be comparable to other IRT based scores, specifically a W-score metric used in many educational tests (e.g., Woodcock-Johnson; Stanford Binet 5). If I run an item-level Rasch using Winsteps, the IRT log ability scores are transformed with the WINSTEPS commands: UMEAN=500; USCALE = 9.1024.
Can anyone tell me how to transform the saved factor scores to this new latent ability scale that is comparable to W-scores generated with Winsteps with the above parameters. Thanks