How Do Junior High School Students Comprehend the Concept of Function?

Abstract

Function is an essential material in mathematics as it is connected to real life very much and cannot be mastered easily, as shown with the findings of researches on the learning difficulty faced by students in the material of function. This qualitative research with data triangulation is designed in case study aiming to explore learning obstacles based on students’ comprehension on concept of function and how students construct meaning related to their learning experience. This research involves 13 (thirteen) 9th (ninth) graders of Junior High School in Gunungkidul Regency having received the material of function. Data were collected through test and interview. Result of interview was transcribed to be analysed in-depth to find out how the students comprehend concept and to identify potential learning obstacles. Result shows that overall, the concept of function is defined as: (1) correspondence between two elements; (2) there is inconsistent/partial definition of function; and (3) some students can define completely but limited to the context of linear function and square function. In conclusion, there is learning obstacle in the concept of function, including epistemological, ontogenic, and didactical. Some attempts or further researches should be conducted to improve the learning of function to enable the students to comprehend completely through, among others: (1) completing the material with the concept map of function family tree; (2) conducting an analysis on the material of textbook using fraxeology; and (3) developing hypothetical learning trajectory and didactic design to overcome learning obstacle.