The aim of this research was to find out whether send problem
technique was effective to teach writing at the second grade students of SMK
Bakti Purwokerto or not. The research was conducted two classes at SMK Bakti
Purwokerto and each class consisted 27 students, as subject of the research. The
writer used experiment as the method of the research. The data were collected
with the test. Based on the calculation, the mean of writing score in experimental
class in pre-test was 41.5 and it improved 64.9 in post-test or after the researcher
gives the treatment for the student by giving send problem technique. The result
improvement from both test was 23.4. Meanwhile the result of t-test was 3.5409
or higher than t-table (2.0066). It means that the hypothesis is accepted and in
significant level. It can be concluded that Send Problem technique is effective to
be applied in teaching writing, especially for giving opinion.