THE DEVELOPMENT OF A FOUR - LAYER CONCEPT DEVIATION DIAGNOSIS TEST FOR GRADE 1 STUDENTS STUDYING SINGLE-VRIABLE LINEAR EQUATIONS

Abstract

This study aimed to 1) develop the four-level diagnostic test for misconceptions in mathematics on linear equations with one variable, for grade 7 students, to 2) examine the quality of the four-level diagnostic test for misconceptions, and 3) diagnose misconceptions in mathematics on linear equations with one variable for grade 7 students. The sample included 338 grade 7 students in the second semester of the 2025 academic year from extended opportunity schools under the Phichit Primary Educational Service Area Office 1 in Phichit, obtained by multi-stage random sampling. The study was conducted in three phases: 1) development of the diagnostic test for misconceptions; 2) development and evaluation of the quality of the four-level diagnostic test for misconceptions; and 3) studying and classifying the students' misconceptions. The findings showed that (1) the four-level diagnostic test for studying 7 misconceptions consisted of three main contents: linear equations with one variable, solving linear equations with one variable, and applying knowledge about solving linear equations with one variable in real life. There were 40 questions, each consisting of A-tier, CA-tier, R-tier, and CR-tier. (2) Regarding the results of the quality check of the four-level diagnostic test for misconceptions, the test had an IOC of between 0.67-1.00, a mean difficulty value of A-tier of 0.40 with values ​​from 0.21-0.68, a mean difficulty value of R-tier of 0.39 with values ​​from 0.21-0.75, a mean discrimination value of A-tier of 0.45 with values ​​from 0.21-0.79, and a mean difficulty value of R-tier of 0.36 with values ​​from 0.21-0.79. The reliability of the test according to the Kuder-Richardson formula (KR-20) was 0.87 for A-tier and 0.82 for R-tier. (3) The results of the diagnosis of students' misconceptions showed that most students were in the group with misconceptions (M), followed by the group lacking knowledge (LK), the group with concept attainment (SK), and the group lacking confidence in knowledge (NCK). The most misconception was substitution in algebraic expressions.