The research aimed to identify (1) whether and to what extent indirect corrective feedback improves students’ writing accuracy and (2) the challenges of implementing indirect corrective feedback in a writing classroom.

The research applied classroom action research as the research design. The research was conducted at SMA Negeri 1 Karanganyar. The research was conducted in two cycles which consist of 4 steps of the classroom action research procedure: planning, implementing, observing, and reflecting on each cycle. To collect the data, the researcher conducted observation, interviews, and tests. The tests were conducted at the preliminary research and the end of each cycle. Those tests were used to measure students’ improvement before and after the research is conducted.

The result of the research indicates that implementing indirect corrective feedback enables students to enhance their writing accuracy. The enhancement of the students’ writing accuracy can be seen in the result of the test. The mean score of cycle 2 shows that there is a convincing enhancement in the students’ writing accuracy. The mean score of cycle 2 is 81. It is higher than the mean score of the pre-research test and cycle 1, which are 65.62 and 74. Among the aspects of writing, the highest to the lowest improvement of each aspect can be seen as follows: 1) language use, 2) content, 3) vocabulary, and 4) mechanics. The second point to be concluded is that even though some challenges of implementing the indirect corrective feedback do still emerge, such as the time constraints, the differences in student's proficiency level in language acquisition, and the students’ motivation, the researcher believes that ICF is still essential to be provided as assistance for students.

In conclusion, implementing indirect corrective feedback can improve students’ writing accuracy. This research suggests that the teacher’s indirect corrective feedback can be implemented as one of the effective strategies in language teaching methodology, particularly for teaching writing.