Special education employs intervention measures (at an individual level) designed to meet the distinct needs of every student. Since it follows a framework that focuses on the individual behavior of students, single subject research can form a basis for enhancing special education. Instead of using a control group and an intervention group to test for the effectiveness of intervention measures, single-based researchers use a single group in their study. Here, researchers vary the research environment in the study group (through the introduction, variation, and withdrawal of intervention conditions). Such a direction helps researchers to note any observable characteristics in a study group that result from intervention measures; thus, helping researchers to establish a functional relationship between variables (Tankersley et al., 2008).
Functional Relationship between Variables
Any valid research must show a functional relationship between variables. In other words, a valid research must clearly show that an intervention measure is leading to some positive behavior among research participants (Tankersley et al., 2008). Here, a clear relationship must exist between an intervention measure and a positive response from learners.
Examples of Group and Single-Subject Research Designs
The examples below demonstrate how a group design experimental approach and a single-subject design can help a researcher to form a functional relationship between two variables. In a group design experiment, the researcher will first need to identify two different groups- a control group and a test group. Importantly, the two experimental groups should as much as possible have similar environments of study to prevent any form of bias in observations (Tankersley et al., 2008). Intervention measures that include the use of positive instructional support by teachers (such as a high frequency in the use of positive words of encouragement) will only apply in the intervention group. On the other hand, no intervention measures apply in the control group. The researcher will then compare the rate of positive social interactions in the two groups. A higher frequency of positive social interactions in the experimental group as compared to the control group will suggest a functional relationship between the use of positive instructional support and positive social interactions among learners (Tankersley et al., 2008).
Unlike the group experiment design, single-subject research focuses on only a single group of study. Here, a researcher can use a multiple-baseline design to conduct this particular experiment. A consistent pattern of behavior under ordinary conditions will form the baseline. Then, teachers will employ intervention conditions in sequence for each student in the study group until all students are covered. To come up with credible results, it is necessary to observe each student in the study group separately. A predominance of positive social interactions from students placed under positive teaching support as compared to those who are not under intervention conditions suggests a functional relationship between positive teaching support and positive social interactions (Tankersley et al., 2008).
Why the Baseline Condition is Important
A baseline condition is prerequisite for single-subject research design. A baseline condition helps to verify an experiment since it assures a researcher that any positive observation is a sole result of intervention measures, and not because of any special conditions within a study group (Tankersley et al., 2008). In addition, a baseline condition helps a researcher to determine a constant pattern of behavior, which helps a researcher to move from ordinary level of performance to intervention performance (Tankersley et al., 2008). Moreover, a baseline condition helps a researcher to establish a stable set of conditions from where he can progress to test for the presence of functional variables (Tankersley et al., 2008).
Important Characteristics of Baseline Research
Every subject-based research must have three important features. First, it must have a consistent, reliable and repetitive system of measuring targeted behaviors (Tankersley et al., 2008). The main aim of using such a system is to guarantee the accuracy and reliability of measured behavior; thus, it is fruitful for teachers to use this approach. Here, several approaches (including a broad system of measurements that focuses on the use of multiple observers and repeated measurements in an effort to come up with consistent results) can help.
Secondly, intervention measures must repeatedly, strategically, and systematically introduce, and then remove intervention measures in experimental groups (Tankersley et al., 2008). The purpose is to allow researchers adjust the presence of and intensity of intervention measures; thus, measure how the experimental group responds to intervention measures. Teachers must also follow the above procedure in their classroom work. Thirdly, single-based research must follow an approach that analyses data separately for each student; thus, allowing teachers to focus on the needs of students at an individual level (Tankersley et al., 2008). Such an approach gives a researcher a chance to verify if an intervention measure is effective. Positive responses to an intervention measure from different students at different times suggest a functional relationship.
Instead of using a control group and an intervention group to test for the effectiveness of intervention measures, single subject researchers use a single group in their study; thus, focusing on the individual needs of special students. Therefore, it is fruitful for all special education professionals to apply some form of single subject research in their daily work. As more progress occurs in the area of research, professionals in special needs education will have an improved platform of practice.
Tankersley, M., Harjusola, S., & Landrum, T. (2008).Using single-subject research to establish the evidence base of special education, Intervention in School and Clinic, 44(2), 83-90.