I am trying to do a research proposal where I planned on doing a pretest-posttest experiment on 2-3 groups of subjects (measure baseline indicators of anxiety, depression, self-esteem, body dissatisfaction, asses that they have all a similar baseline, randomly assign subjects to one of 3 conditions -treatment 1, treatment 2, control group then measure them again afterwards). I want to see if initial indicators changed from the beginning due to treatment and how. Note: the first treatment I anticipate a slight effect in a negative way, that is anxiety, depression etc to be affected slightly whereas treatment 2 I would guess would affect them in a slightly positive way. My coordinate teacher has given me no help here at the methodology part and I, slightly confused by all the research models, got myself stuck. Is this a realistic research design? if not should I remove one treatment or the control group, then which statistical tool should I use to analyze my data? I searched for days for similar designs and have gotten even more confused. I guess I just need a point of direction and the rest I can figure out myself. Please help.
Thank you in advance.