I have data from research that used an experimental pretest posttest control group design. That means I have one categorical independent variable Treatment (0= control group and 1= participant group), Two dependents continuous variable ( before treatment and after treatment) . To be more precise, each individual in each group have participated in the two measurement (before and after).

1. Which appropriate statistical procedure to compare the two groups ( To see the statistical significance of observed difference between control group and participant group ) and to determine the effect size ? I can use. Would you like to explain me how I can proceed using Spss?

I would like to precise that I found that one of the dependent variable is not normaly distributed.

2. If the dependents variables (before and after) were the likert scale ( 1 to 7 : strongly desagree,......., strongly agree), How could I process to reply to the quesion 1. (Both dependent variables are not normaly distributed)

I will appreciate if you could give me more explanation. Thank you