Converting EFA and Cluster Analysis Data to Multi-Dimensional Scaling in Stata

[Jose Tubilleja]

i am doing research on factors of student success using a 40-question survey. The survey is composed of 5-point Likert scale questions. I will be using the same dataset for Exploratory Factor Analysis with factor rotation (EFA), K-Cluster Analysis (CA), and Multi-dimensional Scaling (MDS). I have already completed the design in Stata for the EFA and CA, and have successfully done a practice run with dummy data.

I am now having difficulties with converting the same dataset (of factors) for use with MDS. Basically, I am looking to start with creating a 40X40 correlation coefficient matrix, then square the results. I know the correlate / pwcorr command and the squaring separately, but I just can't find the appropriate combination of commands for doing that and then pass it on to the "mds" command for the MDS solution and map. Is this the proper way or am I going in the wrong direction?

Thank you so much for any help.

Jose

[Jose Tubilleja]

I tried the following approach and it worked. But it's the long process. I'm still missing a command to convert the values in the correlation coefficient matrix to squares. That way, I will not have to export it to Excel, square the values there, and use the revised Excel as the new dataset for the Multidimensional Scaling. Please see below (Stata commands in blue):

1. corr item1-item40
2. select the entire matrix, right-click and "Copy Table"
3. Paste unto Excel and square all the values, save as a new dataset
4. import excel using c:\newDataset.xlsx
5. mds item1-item40, id(item) method(modern) dim(2) nolog

I got my MDS solution and map but I'd rather have a Stata command for steps 2 - 4. I'd appreciate help in that regard.

Jose

[Oded Mcdossi]

Dear Jose Tubilleja you have posted your question in the wrong forum. You should use the General forum for your questions.

[Jose Tubilleja]

Thank you, Oded. I will. Sorry for the confusion.