With this study it is aimed to investigate the effects of instruction based on the Elaboration Theory of Instruction to the academic achievements and retention of 7th grades students of mathematics lesson. The idea that the proposals of the eleboration theory intended to the conceptual and procedural eleborating would be appropriate to understanding the concepts and procedures which required for mathematics instruction and also to the purpose of establishing a relationship between them, the proclaimed research is performed in the maths lessons and it's expected to offer an alternative approach to the educators who are seeking for different teaching approaches which can be used in teaching and contribute to the literature. This study used an quasi-experimental design, with a threatment and a non threatment control group and pre-test, post-test measurements. The sample of study is consisted of the 55 (28 threatment group, 27 non threatment control group) seventh grade students of a secondary public school in Diyarbakir provincy. The classes selected by random method, 7/A is taken as threatment group and 7/D is taken as non threatment control group. The data required for this study is collected by the achievement test of "the Linear and Angles unit" which consisted of 27 questions. The achievement test is used as pre-test and post-test for the threatment and non threatment control group. The same test is given five weeks later for the third time to measure the retention. Independt samples t-test, paired samples t-test and Mann Whitney-U tests are used in analysing the data. The findings obtained from study shows that there has been a signifficant differance in the groups post-test and retention test's mean for the favor of thretament group. It puts forth that the instruction based on ETI which performed on the threatment group increases the academic achievement and retention intended for "the Linear and Angles unit".
The Eleboration Theory of Instruction, Instructional Design, Mathematics Instruction, Linear and Ang