when does it occur during the pre and post intervention phase? how to compare a pre intervention and postintervention difference between post intervention and preintervention can patients have pre-intervention control how to find the difference between pre-intervention and post intervention how to predict the difference between pre- and after intervention calculating the difference in pre and post intervention how do you measure pre intervention outcome? what is the difference between a pre-intervention and post-intervention what is the difference between a pre and a post intervention difference between pre- and post intervention how to evaluate the difference between a baseline and a postintervention intervention how to calculate the difference between the preintervention intervention and postintervention groups? when to assess postintervention variability what is difference between pre-intervention and post-intervention why is intervention pre and post how is pre intervention compared to post intervention data? how to calculate the difference between pre intervention and post intervention? how to calculate pre intervention data which of the following is a pre-intervention control or after intervention?