I have a very time-sensitive question:

I am replicating a theory that uses 12 Likert items to measure three latent variables (4 items per latent variable).

Also in my study I use these 12 likert items that measure three latent variables. Every latent variables is measured by 4 Likert items. For my research, I have to combine/sum these variables into one measurement. So hat I have three variables as a result.

My question/problem is:

**How can I combine these 4 Likert items into one scale**, so that I have one number for each latent variable that I can use for my analysis?

Some extra information:

All the Likert item are measured on a 5-point-Likert scale.

I have already run Cronbach's Alpha in SPSS and the 4 items have a very high Alpha. Also, the "corrected item- total correlation" is high enough.

I want to use the three variables in a ordinal log regression analysis.

Your help is greatly appreciated!