1. The LISREL MODEL and Ordinal Variables Ulf H. Olsson Professor of Statistics

2. Ulf H. Olsson Ordinal Variables In practice, observed or measured variables are ofte ordinal However, ordinality is often ignored and numbers such as 1,2,3, etc. representing ordered categories, are treated as continuous variables. But, this is incorrect!

3. Ulf H. Olsson Estimation 1) No AC provided ML 2) AC provided and Polychoric Correlation WLS (ADF)

4. Ulf H. Olsson Examples Efficacy data From raw data to Model SPSS-file PSF-file