Muhammad Irfan, Toto Nusantara, S. Subanji, S. Sisworo
Proportional problem is a complex issue. What attracts the attention of researchers is the matter of direct proportion and inverse proportion. The two problems are different, but there are similarities that make the student has trouble while solving the problem. The purpose of this study is to describe the interference of students in solving the problem of inverse proportion based on APOS theory. The type of this research is qualitativeexplorative research, that is, the researcher explores how the student’s interference in solving the problem of inverse proportion. Selection of research subjects using purposive technique, namely by considering the answers of students written test. The data collection procedure uses problem-solving and in-depth interviews. The results of this study indicate that students experiencing proactive interference caused by failure to coordinate the knowledge they have with the problems faced. As a result, when resolving the problem of inverse proportion, students are actually using the concept of direct proportion to solve inverse proportion problem. © IJSTR 2019.
Universitas Negeri Malang, Indonesia
