I don’t use AMOS for structural equation modeling all that often and every time I do I have to look up all of the steps again.
1. Install SPSS and AMOS. Fortunately, it seems to work on Windows 8. Yay! You can either open AMOS by double-clicking on it or you can open it directly from the ANALYZE menu in SPSS
2. Go to FILE > DATA FILES > Click on FILENAME and then go to wherever the SPSS file is saved. When you open the file, if you haven’t opened it from SPSS and want to look at the file to be sure you have the right data, if you click on the View Data tab it opens SPSS and the data file.
3. Click on the RECTANGLE (top left corner) and draw a box for each observed variable.
4. Double-click on each box to give it a variable name and label
5. Click on the single arrow to draw paths, the double arrow to draw covariances
6. Include an other term for error variance
7. Set the regression parameter of one of the paths to 1
8. Click on View > Analysis Properties and select Output. If you don’t do this, you won’t get much output and you will be disappointed. At a minimum here select standardized estimates, but you probably want squared multiple correlations and maybe some other stuff too.
9. Select Calculate Estimates
At this point, you may get the dreaded error … Path is not of a legal form.
10. Here is what you need to do – save your file. The AMOS manual says you should be prompted to save your file, but I wasn’t (neither on Windows 7 nor on Windows 8). However, saving the file solved the problem.
My assumption is that AMOS writes output to a path relative to where your AMOS file is saved and if you haven’t saved the file, it causes this error.
So, hurray, hurray it runs and you are looking at the exact same model you were a minute again. Where are the estimates?
11. Click the SECOND button in the top middle pane and change-O presto, your estimates appear on the path diagram. You can also select TEXT OUTPUT under the VIEW menu for some tables.
I’ll finish up this project and several months from now when I’m using AMOS again I’ll be glad I wrote this post.