The aim of this research was to find out the effectiveness of project-based
learning method for teaching writing. This research used quasi experimental, of
which subject the research was class XI AP 3 with 26 students as experimental group
and XI AP 1 with 26 students as control group. Project-based learning method was
applied in experimental group while control group was not taught with project-based
learning method. Test was used for collecting the data, namely pre-test and post-test,
and the instrument was tried out to eleventh grade students of SMK Bakti Purwokerto
to know the effectiveness of the treatment. The test consisted of essay question. After
getting the data, the data was analyzed by using t-test formula. The result of t-test
computation was higher than t-table. It was 2.03 and the result of t-table at significant
level 0.05 with the degree of freedom 50 = 1.67591. It could be concluded that the
hypothesis of the research that project-based learning method was effective for
teaching writing was accepted.