I'm working on SPSS 18, my data base concerning longitude study with two waves for children's (ages 12-18) answers about mental and health problems. Each wave was coded under a different "line", which means I have for the same ID, different answers for the same questions.
Because I need to do correlations and to look for change from one wave to another, how can I merge the two lines (i.e. waves) of the same kid into one line. Which means I'll have the kid's PTSD symptoms from the first wave and from the second wave side by side?.
Thank you very much!