A Development of a Diagnostic Test on the Topic of Fraction for Mathayom Suksa 1 Students

Abstract

            The purposes of this research were: 1) to construct the diagnostic test on Fraction, 2) to validate the constructed diagnostic test, and 3) to determine defective learning on Fraction of Mattayom Suksa 1 students. Samples were 361 students in Mattayom Suksa 1, randomized by two-stage random sampling from schools under the Secondary Educational Service Area 28 in academic year 2016. Research instruments were 6 sets of diagnostic tests.

            The research findings were as follows:

1. The diagnostic test on Fraction for Mattayom Suksa 1 students was constructed on good quality of test, this test comprised 6 parts including basic, comparison, addition, subtraction, multiplication, and division of fractions. This test were 50 items.
2. The constructed diagnostic test was the content validity from 0.80-1.00, the test difficulty from 0.40 - 0.80, and the discrimination from 0.34-0.86. Each subtest had reliability at 0.73, 0.62, 0.84, 0.87, 0.88, and 0.84, respectively. 3. Results on determining defective learning on fractions of students showed the difficulties of each part as follows. Students did not understand fractional numbers and fraction sign, students misunderstood equal fractional numbers, and students were confused with addition of fraction.