The aims of the study are: (1) to develop written-instructional material using Dick’s and Carey’s model accompanied by using cognitive strategies, and (2) to compare the effectiveness of two kinds of written–instructional materials o n student’s achievement. This study was conducted in two phases. The first phase, was developing model of written-instructional material using Dick’s and Carey’s model accompanied by using cognitive strategies. In the second phase, quasi-experimental study was conducted to compare the effectiveness of the model with the existing written-instructional material o n Social Sciences student’s achievement.

The instruments used were: (1) a rating scale by experts (r = .76), (2) student’s response (r = .83), and (3) achievement test to measure student’s achievement o n SMI ( r = .97). Analysis of variance and T-test were used to test the hypothesis at the level of significance a = .05.

The result of the study were two parts. The first part was a written-instructional material o n Studi Masyarakat Indonesia Subject which was developed by using Dick’s and Carey’s model accompanied by using cognitive strategies. In developing the written-instructional material, the researcher conducted eight steps.

The second part of the result of the study was that the written-instructional material developed by using Dick’s and Carey’s model accompanied by using cognitive strategies was more effective in improving social sciences student’s achievement compared to the existing written-instructional materials. (Fo = 57.97 > F(.95; 1.98) = 3.942; to = 7.61 > t(.975; 98) = 1.66).

It is therefore recommended to faculty members of the Department of Social Sciences Education, Sebelas Maret University to develop written-instructional material based o n the principles of well known instructional model accompanied by using cognitive strategies.

Key words : written-instructional material, cognitive strategies, student’s achievement.