Development of Teaching Material Based Environment on Report Text Grade X Pelayaran Buana Bahari Medan Vocational High School

The aim of this research is to determine: (1) the contruction of teaching material based environment on report text; (2) validating teaching material; and (3) the effectiveness of teaching material based environment on report text grade X Pelayaran Buana Bahari Medan Vocational High School. This research use model of the reseach and development Borg and Gall which adapted from Sanjaya. Data collection techniques in this research include observation, questionnaires, and essay test report text. The result of this research shows that: (1) material validation include content feasibility, the feasibility of presentation, and the feasibility of languange with the average percentation 92,89 % on very good criteria; (2) design expert validation with the average percentation 86,31% on very good criteria; (3) the effectiveness of teaching material shows that posttest percentation 85,50% higher than the pretest percentation 76,17%. Keywords: development, teaching material, environment, report text