Thursday, June 2, 2011

Final Project

Do we need to attach the SPSS output for the final project?

Also, what graph do we look at for assumption 3 (relationship between IVs and DV)?

4 comments:

David said...

Yes, like your other HWs, include your SPSS output.

The answer to your other question is in the notes on Assumptions (both ppt and doc) under the heading "Detecting Violations."

Diana Ro said...

Hi David. I look there and it says to plot the IVs and the DV, but how do I do that? Scatterplots? And if so, there's 4 IVs so how do I put it all in there? Or do I do 4 separate ones?

David said...

You can plot the residuals vs. the predicted. The other way to look is to plot the residuals vs. the IV. The first is probably easier.

When you run the regression, you can click on "Plots." There you can select *ZRESID and *ZPRED to plot.

You wouldn't be able to do all your IVs at once, so do it separately for each IV.

For reference, if anyone wants to do the other plot, you'd have to save the residuals by clicking "Save" in the regression dialog box and selecting the residual you want. That'll create a new variable with the residuals. Then you can create a scatterplot via Chartbuilder or Legacy Dialogs.

David said...

I'm sorry, you actually can look at this assumption all together in the full model. You can ask SPSS to plot *ZRESID and *ZPRED for all the IVs at once.