For my thesis I have to work with sleep diaries, but I'm having some trouble computing the variable Total Sleep Time & Sleep Efficiency. The problem is this:
- one question in the diary is: what time did you close your eyes to go to sleep? I typed the answers in SPSS like this: 22:00h or 0:00h for example.
- another question is: what time did you get up? I typed the answers in SPSS like this: 08.00h
Now I have to compute the time a participant slept, spent in bed (minus wakefulness after sleep onset). How can I compute that with SPSS?
I hope someone can help me!