The Effectiveness of the Direct Instruction Model in Teaching the Properties of Matter Unit to Students with Learning Disability and Typically Developing Students

Introduction: This study examined the teaching of the "Properties of Matter" unit in science education to students with learning disability (LD) who are in mainstream inclusion programs and typically developing students (TDS) in 4th grade elementary school, according to the Direct Instruction Model (DIM), and investigated the effect of this model on students' learning outcomes.Method: To determine the effectiveness of instructional materials developed according to DIM, a multiple probe design across subjects from single-subject designs was employed for one-on-one studies, while a single-group pretest-posttest design was used for group studies. Data obtained from one-on-one studies were analyzed using line graphs, while the group study was analyzed using the paired sample t-test, a parametric test.Findings: Following the intervention using instructional materials developed according to DIM, all students showed significant differences in their scores from pretest to posttest. Additionally, after the intervention, students with LD demonstrated parallel development to other students in the group in terms of learning the subject matter. When the development of students with LD was monitored, it was determined that students' learning was retained. When examining the findings obtained within the scope of social validity objectives, it was determined that all students and teachers who participated in the intervention using instructional materials developed according to DIM were satisfied with participating in the study and the instructional process.Discussion: Following one-on-one and group intervention using instructional materials developed according to DIM, it was observed that all students met the necessary objectives for the science unit on properties of matter. Furthermore, evaluations conducted during the continuation of the instructional process determined that the acquired knowledge showed retention and that students generalized this information. Regarding the intervention process, the positive feedback from students and teachers suggested that the instructional materials were socially valid. In similar studies, instructional tools can be developed and implemented for different topics within the science curriculum.