Advances in Social Science, Education and Humanities Research (ASSEHR), volume 247 International Conference on Science and Education and Technology 2018 (ISET 2018) Learning Similarity Lawang Sewu using Context for Third Grade Lower Secondary School Students Achmad Fahrurozi1, Suci Maesaroh2, Imam Suwanto3, Farida Nursyahidah4 1,2,3,4 Faculty of Mathematics and Natural Science Education and Information Technology, University of PGRI Semarang, 50125, Indonesia 4Corresponding author e-mail: [email protected] Abstract This study aims to produce a learning trajectory by using the context of Lawang Sewu in helping students to understand the concept of similarity. The approach used in this research was Realistic Mathematics Education, in Indonesian version is called by PMRI. Subject of the study is the third-grade students of SMP 37 Semarang, Central Java, Indonesia, involving 6 students who were chosen in heterogeneous capabilities. The methodology used is a design research consisting of three phases, namely the preliminary design, the design experiment, and the retrospective analysis. However, this study only shows the results in the design experiment phase, in particular on a pilot experiment. Data collection was done through several techniques, namely: video recordings, photograph, students work result, and students interview during learning. Student learning activities consist of four activities, namely observing the Lawang Sewu video, identifying two similar shapes, identifying the requirements of two similar shapes, and solving a contextual problem related to similarity. The results of this study indicate that through a series of activities that have been designed could help to stimulate students understanding of similarity concept by using Lawang Sewu context. Key words: Similarity, Design Research, PMRI, Lawang Sewu Context 1. Introduction improved (Abdussakir, 2009). The lack of the Mathematics has an important role in our students to solve the similarity are 1. Students daily life. In addition, Mathematics is a science difficult to determine two similarities or more 2. that has many parts with an unlimited span and Students are able to solve similarity through the depth (Ilgar, 2013). One of the important correct way but the result incorrect. 3. Students learning areas in mathematics and also the oldest are able to solve the question and get a good branches in mathematics is geometry (Fidan, result but incorrect way (Nafiin, 2018). The 2010). Based on the distribution of education difficulty of students in understanding the standards for junior high school, geometry material shown by students is still weak in material has a large portion (41%) compared to understanding the concepts and principles of other materials such as algebra (29%), numbers geometry. Difficulties can be changed by several (18%), and statistics and probability (12%) factors including internal factors (from within (Putra, 2013). Within the knowledge of students) and external factors (external mathematics, the things learned in geometry are environment of students). One of the external shapes and space (Senechal, 1990). In line with factors that influence student difficulties is this, Reference (Sahin, 2008) stated that by teacher-centered learning (teacher center). mastering geometric thinking skills, students Learning that complies with the teacher planning will be able to have an ability of problem- the difficulty of learning goals will reach. The solving, critical thinking, and a better purpose of mathematics learning itself is the understanding of the other subjects in learning process that focuses on children to mathematics. Reference (Ruseffendi, 1991) apply it. This is consistent with (Kemendikbud, asserted that one of beneficial in learning 2016) composing on the modern pedagogical geometry is to developing logical thinking skill dimension of learning, namely using a scientific and making true generalization ability. (scientific) approach. Moreover, the students who acquire the ability To overcome this problem one of the and habit of problem solving in school tend to approaches that can be used in the learning be individuals who can solve the problems in the process of mathematics is Indonesian Realistic social life in their future (Sahin, 2007; Turgut, Mathematics Education (PMRI) by using the 2007). right context. An effective PMRI approach to On the other hand, the ability of students in improve understanding of mathematical learning geometry is still low and need to be concepts because the PMRI approach is a Copyright © 2018, the Authors. Published by Atlantis Press. 32 This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/). Advances in Social Science, Education and Humanities Research (ASSEHR), volume 247 process that constructs knowledge. This is in designing instruments to evaluate the accordance with the result of some studies learning process (Nursyahidah, 2014; Prahmana, 2012; At this stage HLT designed containing Nursyahidah, 2018; Saputro, 2015) stated that anticipate things that might happen. Before PMRI approach involved in learning that is designing, the researchers set learning goals more concerned with student activities in the or targets will be achieved and the starting learning process in the classroom. Students are point of learning. Some things you do at this able to build their own knowledge of the stage is: (1) review the literature regarding problems that exist in mathematics. the material similarity to the curriculum in There are several contexts used in PMRI 2013 revised edition, 2017, (2) designing the research, for instance, traditional games HLT to the context lawang sewu as the basis (Nursyahidah, 2013; Prahmana, 2012), folklore, of its alleged strategy of beginning students, legend (Widyawati, 2016). In this study, the (3) designing an interactive video that will is context to support the PMRI approach is used as a medium for learning, and (4) Lawang Sewu which is a historical building in discuss with professors, teachers, and Central Java. The Lawang Sewu context is research experts. chosen because not only it has already familiar b. Design Experiment to students in Semarang but also it can represent In this second phase, the researchers similarity of two-dimensional shapes. The shape tested the design as found in the first phase of of the components of that building like doors, activities. The trial is aimed at exploring and windows, pictures, and park as a model that guessing strategy and thinking students allows representing some two-dimensional during the process of the true learning. Stage shape that similar. trial design is divided into two phases, To implement the study, the authors used namely that the pilot experiment and design research method. It consists of three teaching experiment. phases, namely: preliminary design, experiment The pilot phase of this experiment also (a pilot experiment and teaching experiment), referred to as a bridge between the early and retrospectively analyze. But this current phase of learning the experimental stage. The study was limited to the pilot phase of the purpose of this experiment was to test initial experiment. From the above discussion, the HLT. The research will be made up of researchers conduct a research with the aim of several things: a pilot experiment, which developing a theory of learning to assist students tested the HLT has been designed in a small to understand the concept of the similarity using group that involves high ability students, Lawang Sewu context. medium, and low respectively 2 children. Furthermore, researchers did Teaching 2. Methods experiment, which tested the HLT that has The method used in this study is a design been designed, tested on a small group, and research which was designing learning similarity fixed in the actual class that is the subject of material for the third-grade students. The subject research, observation; and perform tests. of this study was 6 students of ninth grade c. Retrospective analysis students of SMP Negeri 37 Semarang. This Some of the steps to be taken at this research was conducted in the second semester stage include: (1) analyzing the data have of academic year 2017/2018. been obtained from the stage of teaching, Design research is a method aiming to experiments, and the results of the analysis develop the Local Instructional Theory (LIT) to are used to plan activities and develop a plan improve the quality (Bakker, 2003). In this of activities in the next learning, (2) study, the developed design was Hypothetical comparing the HLT with students learning in Learning Trajectory (HLT) which contained a the real, the results are used to answer the series of students’ learning activities. According problem formulation. The goal is to develop to (Gravenmeijer, K & Cobb, P. 2006) a theory of local instruments. The techniques instructional design is done in this study of collecting data to answer the research consisted of three phases, namely: problems through observation, interview, and a. Preliminary Design documentation. The main objective at this stage is to The purpose of the observation is to get the develop a sequence of learning activities and idea of dealing with the social norms that apply 33 Advances in Social Science, Education and Humanities Research (ASSEHR), volume 247 mathematics in the classroom, the teaching apperception by asking, "Is there any one of methods used, class organization, the rules of you who have been there?",