Exactely what kind of data will be produced by the sexual assault questionnaire, e.g.
one global score? A yes/no assessment? An ordinal measure? Or maybe several scores?
Same with stress measurement: is it one score or are these several scores, and on which
scale level? On which scale will school grades be measured here?
Maybe you could provide some background: how is your population defined, how will
your sample be recruited, and how large will the sample be? Have you already an idea
about the prevalence rate of sexuals assaults in your target population?