However , in single - subject designs , these decisions are often made as the data are collected .
Research designs are traditionally preplanned so that most of the details about to whom and when the intervention will be introduced are decided prior to the beginning of the study .
In single - subject designs , these decisions are often made as the data are collected .
Research designs are traditionally preplanned so that most of the details about to whom and when the intervention will be introduced are decided prior to the beginning of the study .