This study aimed to determine the effect of Task-Based Language Teaching (TBLT) on students’ ability to write procedure texts at SMKN 4 Palembang. This study employed a pre-experimental one-group pretest-posttest design. The participants were 21 eleventh-grade students assigned by the school. Data were collected through writing tests administered before and after the treatment. Students’ writing performance was assessed using an analytical scoring rubric adapted from Brown (2004), covering five components: content, organization, grammar, vocabulary, and mechanics. The data were analyzed using SPSS through reliability testing, normality testing, descriptive statistics, and a Paired Samples T-Test. The overall results showed an improvement in students’ writing performance after the implementation of TBLT. The mean score increased from 87.02 in the pretest to 91.17 in the posttest. The pretest scores ranged from 84 to 90, with a standard deviation of 1.834, while the posttest scores ranged from 88 to 94, with a standard deviation of 1.742. The Paired Samples T-Test produced a significance value of 0.000 (p < 0.05), indicating a statistically significant improvement in students’ writing performance after the treatment. Significant improvements were also found in all five writing components: content (p = 0.001), organization (p = 0.001), grammar (p = 0.000), vocabulary (p = 0.001), and mechanics (p = 0.000). In addition, TBLT encouraged active participation and supported the development of critical thinking, communication, collaboration, and creativity. Therefore, the findings indicate that TBLT had a positive and statistically significant effect on students’ ability to write procedure texts.

Keywords: Task�Based Language Teaching, Writing Ability, Procedure Text, Writing Performance, 21st�Century Skills