Sample Size Help for Observation Study

#1
I wanted to calculate sample size for a single group, observational study. I'll be using a questionnaire to predict outcome (i.e. score on another questionnaire) in a sample of participants but I don't have a comparator or control group. How would I calculate sample size for this type of study design? Thanks!
 

hlsmith

Omega Contributor
#4
How is the variables formatted, what is your tentative sample size or pool to draw from and most importantly do you have a hypothesis. If so, what is it???
 
#5
I'm looking at whether scores on a self-report questionnaire about sleep predict functioning (based on total score of another questionnaire). I'm able to draw for a pool of approximately 400 people.