<![CDATA[The aim of learning to write is not just to teach writing theory, but to practice writing so that they can produce a text. The integration of learning materials should be in line with the practices carried out by the teacher. This is what makes it difficult to combine the writing learning process to improve students' quality in writing. Students' low ability to write is influenced by internal factors (less interesting learning process) and external factors (less supportive environment) for students. To help with internal factors, developing a writing learning model with guided inquiry based on experimentation. This model is designed according to students' problems and needs in writing. This model was developed using the Plomp development model which consists of a preliminary study, prototype stage and evaluation. Each stage of this research was passed and carried out to see the validity, practicality and effectiveness of the model developed. This research was conducted at a high school in Medan City by taking samples using purposive sampling as an object for testing the model developed. Data collection instruments were carried out using tests, observation sheets and questionnaires. The data obtained consists of data on model validity, model practicality, and model effectiveness. Referring to the data obtained, the results of this research show that the experimental-based guided inquiry model that was tested was valid (feasible) to be tested, practical (easy to use), and effective (increasing students' ability) in writing texts. This can be seen from the data that the increase in students' writing competence is seen in terms of the quality of the texts written by students.]]>
