CONDUCTING ENGLISH TEACHING BY USING DIFFERENTIATION INSTRUCTION IN 21 st CENTURY: A STUDENT-CENTERED APPROACH

In one class, there are various students with different characteristics and learning styles. To achieve the learning objectives, the teacher should apply differentiation instruction. In this study, the concept of differentiation instruction is implemented in learning English, a student-oriented approach. The data sources take from learning outcomes conducted in XII MIPA 1 at SMA Negeri 5 Medan in their process of doing the project. The material taught by the teacher in proving this concept is Conditional Sentence Type 2. The learning method used is project based learning. The learning process carried out for this research lasted for four meetings. This research wants to prove that implementing the concept of differentiation instruction can make the students think ingenious while working with groups to produce the original product. In another words, this research aims to prove the teacher's way of conducting the learning process by implementing the concept of differentiating instruction to produce creative and original products. This concept needs to be implemented so the students can apply Conditional Sentence Type 2 into their daily lives. The result shows each group could work together as a team to produce poetries and songs by using Conditional Sentence Type 2. Each group was enthusiastic to perform their best work in front of the class. Also, the learning process became purposeful and meaningful.


INTRODUCTION
The Indonesian nation consists of various cultures, languages, religions, ethnicities, tribes and local wisdom. This diversity makes the Indonesian nation grow and develop in a social community consisting of various cultural backgrounds. In one class, of course, it consists of heterogeneous students, that is, having a variety of student profiles consisting of various ethnicities and cultures, social status, interests, early abilities, learning styles, and motor development. Over the last twenty years, the curriculum in Indonesia has changed to suit the times and this has certainly had an impact on the language learning process. The latest curriculum launched by the Ministry of Education and Culture today is the "Kurikulum Merdeka", which is a curriculum with various intracurricular learning where the content will be more optimal so that students have enough time to deepen concepts and strengthen competence. In the learning process, the teacher has the flexibility to choose various learning tools so that learning can be adapted to the learning needs and interests of students.
In today's era, language learning does not only aim to produce students who can understand learning material well, but they must also be able to implement the knowledge gained in class into their daily lives and be able to produce creative and original work. 21st century learning focuses on students, one of the factors that must be known by the teacher in carrying out learning in the classroom is that the teacher must know all the profiling of students. So, in implementing English learning, teachers need to know the learning styles of all students in the class so that learning objectives can be achieved.
Learning styles are simply different approaches or ways of learning. The more teachers understand "how" students learn best, the better equipped teachers are to provide instruction and assessment practices that maximize learning outcomes (Haley, 2010:11). Fleming & Mills (1992) classifies learning styles known as VARK. The acronym VARK stands for the VARK modalities -Visual, Aural, Read/write, and Kinesthetic -sensory modalities that are used for learning information. According to Haley (2010) there are basically three types of learning styles: visual, auditory, and kinesthetic. Learning English, by understanding students' learning styles, is an important thing that teachers must do so that teachers can design student-centered learning. Teachers can make observations about the learning styles of their students so they can design learning and classify students based on their learning styles, a fundamental thing in carrying out differentiation instruction. When teachers differentiate instruction, they move away from seeing themselves as keepers and dispensers of knowledge and move toward seeing themselves as collaborators with students and organizers of learning opportunities (Tomlinson, 2017: 34). While content knowledge remains important, these teachers focus less on knowing all the answers and more on "reading" and guiding their students. They work persistently to understand their students' cultures, backgrounds, interests, strengths, and needs. Tomlinson (1999) provides the most well-known definition of differentiated instruction. Tomlinson (1999: 15) defines differentiated instruction as "a teacher's response to learner's needs guided by general principles of differentiation such as respectful tasks, flexible grouping, and ongoing assessment and adjustment. This definition is helpful as it provides us with the variables teachers can modify to meet different student needs. However, there are unlimited combinations of possible teacher responses, including those that modify content (what is taught), process (how students learn), product (how students demonstrate learning), as well as those that adjust instruction in terms of student readiness, interests, and learning profiles (Bondie & Zusho, 2018: 16). Tomlinson (1999) provides multiple descriptions and examples of teachers at work creating differentiated classrooms. Tomlinson stresses the importance of the teacher being a guide and facilitator who accommodates student differences. According to Tomlinson, there are three aspects of differentiating: 1. Content. Concepts, principles, and skills that teachers want students to learn. 2. Process. Activities that help students make sense of, and come to own, the ideas and skills being taught. 2. Products. Culminating projects that allow students to demonstrate and extend what they have learned.
The technology allows for differentiated learning, the ideas of technological integration anchored in phrases, such as anticipating learning, grabbing attention, accessing content, transparency, personalization, processes, culture, authenticity, and product (Miller et al. 2019: 17). Miller et al. (2019: 18) also stated that there are just a few ways differentiating through tech can improve your teaching practice: 1. Create and maintain highly engaging learning experiences. 2. Deliver meaningful, truly authentic instruction. Meet more students' specific needs and engage their interests (to the point that they'll think, "Wow, this class was made for me!"). 3. Transform your classroom into a student-centered environment by empowering your learners to do the heavy lifting intellectually and academically. 4. Help students understand how they think, so they better know how to learn (metacognition). 5. Make teaching easier and more fun! In realizing the curriculum paradigm "Merdeka Belajar" which is aligned with 21st century skills, learning models that hone critical thinking, independence, creativity, and collaboration play an important role in the digital era, therefore the learning that researcher applied in class is students-centered learning by applying a project-based learning model. Project-based learning (PBL) is a learning-bydoing educational approach that is rooted in the work of Dewey and oriented around student engagement in sustained, collaborative, and authentic problem solving activities (Blumenfeld et al. 1991). Solomon (2003) explains in project-based learning, students work in groups to solve challenging problems that are authentic, curriculum-based, and often interdisciplinary. Learners decide how to approach a problem and what activities to pursue. They gather information from a variety of sources and synthesize, analyze and derive knowledge from it. Their learning is inherently valuable because it's connected to something real and involves adult skills such as collaboration and reflection. At the end, students demonstrate their newly acquired knowledge and are judged by how much they've learned and how well they communicate it. Throughout this process, the teacher's role is to guide and advise, rather than to direct and manage, student work.
Based on the background that has been described above, this study aims to implement the concept of differentiation instruction in English subjects for students of XII SMA. The material that the researcher teaches is Conditional Sentence Type 2. Also, the learning model applied by the researcher is projectbased learning by grouping students based on their learning style. The aim of implementing the concept of differentiation instruction is that it is hoped that the learning process can unify the diversity of the characteristics of students by first identifying their learning styles. Then, in the end students can produce creative and original works with the help of technology.

METHOD
This study employs classroom action research, which means research conducted in a class to find out the effects of actions applied to a research subject in that class. This problem was raised based on the findings or learning outcomes obtained in the first and second learning meetings as well as observations made by the researcher in the classroom. So, it is necessary to find the right solution to improve the learning process and improve student learning outcomes. The final results obtained are in the form of creative and original songs or poems and are presented by each group.
In this study, the researcher used a research model that refers to the research implementation process put forward by Kemmis & Mc. Taggart (1992), the implementation of this research consisted of four stages, namely (1) Planning, (2) Acting, (3) Observing, and (4) Reflecting. The learning model used in this classroom action research is a project-based learning model. Meanwhile, The George Lucas Educational Foundation (2003) explains the learning steps using the Project Based Learning (PBL) learning model as follows: 1. Question: Start with the Essential Question. Take a real-world topic and begin an in depth investigation. Make sure it is relevant to your students. 2. Plan: Plan which content outcomes will be addressed while answering the question. Involve students in the questioning, planning, and project-building process. The teacher and students brainstorm activities that support the inquiry. 3. Schedule: Teacher and students design a timeline for project components. Set benchmarks. In other words, this study focuses on the problem of applying differentiation instruction to get creative and original work in class XII MIPA 1 SMA Negeri 5 Medan. The researcher also doubled as a teacher who taught Conditional Sentence Type 2 material for this study. By applying the projectbased learning model, the researcher conducts learning for four meetings to get the expected product results. The data generated is qualitative in the form of songs or poems produced by each group.

FINDINGS AND DISCUSSIONS
This research starts from the planning stage. At this stage, the researcher designed four meetings to study Conditional Sentence Type 2 which took place at XII MIPA 1 at SMA Negeri 5 Medan. The plans that have been made are as follows: 1. At the end of the first learning meeting, the researcher always gives students the form of discussion activities to determine the learning process for the next meeting, whether students have understood today's lesson or not. If the results of the discussion are not optimal, then at the second meeting the researcher must re-emphasize the material being taught before entering the projectbased learning model. At the first and second meetings, students were grouped regardless of the type of learning style so that the researcher could compare the results of the discussions at the first and second meetings with the results of the discussions at the third and fourth meetings. 2. At the third meeting, the researcher must be able to direct students so they can optimize the project they will present at the last meeting. The strategy that the researcher did was to divide the groups according to the learning styles of these students. It is intended that each member of the group can cooperate in determining ideas and cultivating their creativity to produce creative and original work. 3. At the last meeting, students who have worked together in groups can display their work. The application of the project-based learning model to Conditional Sentence Type 2 material aims to enable students to apply this material to their lives and grow their confidence to appear and be able to speak using Conditional Sentence Type 2.
Then, the second stage is the implementation of the action. The results of the meeting obtained were: At the first meeting, students are invited to group discussions to discuss several things that must be known related to social functions, text structures, and linguistic elements of Conditional Sentence Type 2. The discussion questions are as follows:  At this stage, the researcher also carried out the observing stage, namely by observing the results of group discussions at the end of each study. After the lesson ended, the researcher examined the results of student group discussions and found many misconceptions about the concept of students' understanding of the topic Conditional Sentence Type 2, one of the problems was that students could not distinguish between the types of Conditional Sentences.
Referring to the findings of the problem, at the second meeting the researcher explained in detail the topic of Conditional Sentence Type 2 and asked students in groups to analyze the results of other group discussions so that they both learn, understand, and can correctly interpret social functions, text structures, and linguistic elements of Conditional Sentence Type 2. The discussion questions are as follows: 1. What are the misconceptions of the other group? By following the clue: What are the differences between Conditional Sentence Types 1, 2, and 3? 2. Each of you, please make one sentence of Conditional Sentence Type 2 based on your real situation and don't forget the facts! Figure 3. Concrete evidence of the results of group 2 discussions at the second meeting Figure 3 proves that students are able to correctly interpret their understanding of the Conditional Sentence Type 2 topic from the activities of analyzing misconceptions carried out by other groups. Group members have started to use technology to find Conditional Sentence Type 2 material from other sources. In addition, groups can present the results of their discussions using Canva's platform technology. At the third meeting, the researcher first made observations to determine the learning styles of students at the beginning of the meeting. Then, the results of these observations are used as a reference for dividing groups according to the learning styles of students. The results of the division of the groups obtained are as follows: Groups are divided based on student learning styles, students begin discussing the work they will present at the next meeting. The teacher's role here is as a facilitator to direct all groups in conceptualizing the work they will produce. In the fourth meeting, all groups presented their best work in front of the class. The works displayed use technological assistance, such as adding background sound using Bluetooth audio. At this meeting, the researcher also conducted a reflection stage which aimed to evaluate the work of all groups. All groups have worked hard to present their best creative and original work.

DISCUSSION
Implementation of differentiation instruction in class XII MIPA 1 SMA Negeri 5 Medan has a significant impact on student learning outcomes. In the first and second meetings, the researcher only asked students to discuss in groups without grouping students based on their learning styles. Then, the results of group discussions at the first meeting showed that students still did not understand Conditional Sentence Type 2 material correctly. Therefore, at the second meeting, the researcher again strengthened students' understanding of the material and students held discussions with the same group at the first meeting to analyze other groups' misconceptions.
The learning outcomes obtained in the second meeting were that students were able to analyze misconceptions regarding the topic of Conditional Sentence Type 2 which they had discussed previously in the first meeting. Second, students are able to realize what they don't understand, so they look for various sources on the topic of Conditional Sentence Type 2 and listen to the teacher's explanation. Then, they can reflect on the misconceptions they had in the first meeting and make it an experience so they can learn from their mistakes.
After that, at the third and fourth meetings, the researcher carried out the Project Based Learning (PBL) learning model with the final result in the form of creative and original poems or songs that had been made by each group. At the fourth meeting, all groups successfully presented their best work in front of the class using technology. The researcher has implemented three aspects of differentiating according to Tomlinson's theory (1999). The details of the learning activities can be seen in Table 2. Before grouping students based on learning styles, the researcher first grouped students without looking at student learning styles. Then, the researcher reflected at the end of each meeting based on the results of each group's discussion, whether all students had understood the Conditional Sentence Type 2 material or not. The results of the discussions at the first and second meetings can be used as a

Reflecting
benchmark for learning at the next meeting. Then, after making observations, the researcher grouped students based on their learning styles, namely visual, auditory, read/write, and kinesthetic. Then, the researcher facilitated students by displaying learning materials according to the learning styles of all students. Then, the researcher becomes a facilitator to direct all groups to be creative in making creative and original works. The work must contain material content that students have studied before.

Products
Each group produces works in the form of poetry and songs. The works that are produced are so creative because they are accompanied by background sounds or musical instruments and are original because the lyrics of the poems and songs lyrics are based on the ideas of the students.

CONCLUSION
Differentiation instruction is a new learning concept in education in Indonesia because differentiation instruction has just been introduced in the Kurikulum Merdeka. Therefore, there are still many classroom action research researchers who do not understand the application of learning concepts that can accommodate all the learning needs and interests of students in their class. In this study, the researcher applied differentiation instruction by grouping students based on their learning styles so that students could apply Conditional Sentence Type 2 material to their daily lives.
The relationship that is built between teachers and students in the application of differentiation instruction has an impact on student learning outcomes. The result shows that each group could work together as a team to produce poetries and songs using Conditional Sentence Type 2. Each group was enthusiastic about performing their best work in front of the class. Also, the learning process becomes purposeful and meaningful.