I would like some help on the following:

1) I am having trouble with finding the way to incorporate SD line (vertical) in the line graph in SPSS. Could you guide me to the right place?

2) I have ordinal variables (items), but if I added the scores of a few or several items to make up a factor or domains for example, the nature of the ordinal variables become more continous and can be treated as such in SPSS?

3) When I compare two populations (one with 150 people, and more normal and the other with 40 people with some illness) using t test (I guess I should use t test rather than z), how can I get the effect size (how much they differ) for certain variable? Should I enter into SPSS the Mean and SD from each population and then compare?

Please help me on these three things. Thank you.
Thank you,
1) I am talking about the standard deviation (SD) line. I see some people present beautiful graphs (line) with vertical line for each X value. I just wonder if SPSS has the function.
3) Please forgive me for asking this again, but how do I enter and compare the data that are in separate file?


TS Contributor
Those are called "error bars" - I'm pretty sure SPSS has that feature, because I've used that graph before.

To compare data from another file, I would just copy/paste the data into the same file - make new variables or case descriptions if necessary.