Assessing the relative effects of interventions in students with mild disabilities: Assessing instructional time

Assessment data are used to make treatment recommendations for students with mild disabilities. However, no assessment procedures exist that allow one to predict with certainty that one academic intervention will be more effective than another academic intervention for a particular student with mild disabilities. Therefore, hypotheses regarding intervention effectiveness should be tested by assessing students' learning rates under different instructional procedures. In this demonstration, alternating treatment designs are used to show how more precise measurement of instructional time can impact the assessment of relative learning rates when students are exposed to more than one intervention. Discussion centers around the importance of time as a contextual variable when assessing the effects of academic interventions.