Analyzing the efficiency and effectiveness of the use of diagnostic branched tree technique for the teaching of the science lesson to a student with intellectual disability

This study aimed to analyse the use of the alternative evaluating technique of diagnostic branched tree in the science course in the setting of a special education class. To this end, a student with intellectual disability in a special education class was taught the subject of "Digestion of Foods" through a plan that included the alternative evaluation technique of the diagnostic branched tree along with direct instruction, whereas a plan employing direct instruction techniques only was used for the teaching of "the Excretory System". The efficiency and effectiveness of both plans in the learning outcomes were compared through the use of adopted alternating treatments design of single subject designs. An 11-year old female student with mild intellectual disability attending the special education class in the province of Bolu participated in the study. Data were gathered through a teacher interview form, criterion-referenced assessment tools for Digestion of Foods and the Excretory System, and social validity data collection form. Data on efficiency were analysed graphically, while data on social validity collected from the special education teacher of the course were analysed quantitatively. The findings suggested that the topic of Digestion of Foods, the plan for which employed the alternative evaluation technique of diagnostic branched tree in addition to direct instruction, and the topic of the Excretory System taught through a plan consisting of direct instruction techniques only were both acquired successfully by the student. Furthermore, the two plans did not significantly differ in terms of efficiency. As the two plans were compared for the effectiveness data, a plan that included the alternative evaluation technique of the diagnostic branched tree along with direct instruction was found more effectiveness than a plan employing direct instruction techniques only. The opinions expressed by the special education teacher at the end of the study as well as the findings of the social validity revealed that the technique of diagnostic branched tree employed in this study could contribute to the development of students' cognitive skills and facilitate the establishment of an effective learning-teaching environment in the science courses in special education classes. In addition, it was reported that the student adopted a positive attitude towards the science course following the study, increasing her achievement in science course.