Instructional Effectiveness and Instructional Efficiency as Considerations for Data-Based Decision Making: An Evaluation of Interspersing Procedures

Article excerpt

Abstract. The current study investigated the extent to which considering instructional time and student learning rate affects academic treatment decisions. Five second-grade students with difficulties in spelling were exposed to three spelling interventions (traditional drill and practice, interspersal training, and high-p sequencing). Using an alternating treatments design, student performance was measured and graphed in two ways, cumulative learning (a measurement that does not consider the amount of instructional time) and student learning rate (a measurement that does consider instructional time). These two measurement procedures were then compared on their ability to detect differential effects of interventions on spelling mastery. Results suggested that the cumulative learning measurement did not facilitate data-based instructional decision making (i.e., did not show differentiation across conditions); however, the more sensitive measurement that accounted for instructional time (i.e., student learning rate) did. Similar results were found for maintenance data. Discussion focuses on (a) the importance of considering instructional time when making treatment decisions and recommendations, (b) implications for future practice, and (c) directions for future practice and research.

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The majority of students referred to school psychologists have academic skills deficits (U.S. Department of Education, 2000). One role of the school psychologist is to provide recommendations for instructional interventions designed to prevent and remediate academic skill deficits. Regardless of classification (e.g., learning disabled, low achiever), if students learn at the same rate as their peers, then they may never even be considered for special education service (Skinner, Belfiore, & Watson, 1995). Furthermore, enhancing learning rates of those who have already fallen behind their peers is the only way to fully remediate student skill deficits (Skinner, Fletcher, & Hennington, 1996).

School psychology researchers have begun to develop and empirically validate strategies and procedures that have been shown to enhance academic skills. Although many interventions can enhance learning (i.e., they are effective), not all interventions are likely to be equally efficient (i.e., result in equal amounts of learning in the same amount of instructional time). In order to prevent and remedy academic skill deficits, school psychologists should determine which interventions are most efficient by measuring students' learning rates under different instructional conditions (Skinner et al., 1995).

Skinner et al. (1995) demonstrated the importance of considering efficiency. In this study, researchers compared the effects of two taped-words interventions on student learning using two different dependent variables. During the slow taped-words intervention, words were presented every 5 seconds. During the fast taped-word intervention, words were presented one immediately after the other. When data were analyzed with respect to the number of words read correctly per session, results showed that the student learned more words under the slow taped-words intervention. If one were merely concerned with intervention effectiveness, then the intervention selected for the student would be the slow taped-words intervention. However, when data were graphed with respect to learning rates (e.g., number of words learned per minute of instructional time), results showed that the rapid taped-words intervention was superior. In a replication study, Watson and Ray (1997) reported similar findings.

Other researchers demonstrated how considering efficiency can alter decisions with respect to which mathematics intervention is most effective (Skinner, Belfiore, Mace, Williams-Wilson, & Johns, 1997; Skinner, Ford, & Yunker, 1991). In these studies, interventions were equated with respect to the number of opportunities to respond, but made more efficient (e. …