The effects of problem-based learning on students’ cognitive achievements in some selected topics in Chemistry

Abstract

The purpose of the study was to determine the effects of problem-based learning on students‘ cognitive achievements in some selected topics in chemistry. The research design employed for the study was Quasi-Experimental specifically non-equivalent control group pretest–posttest design. The total population considered for the study consisted of Two hundred and fifty (250) second year senior high school students‘ who learn chemistry as an elective subject in Nkrankwanta Senior High Technical School. The sample size was Eighty-five (85) elective chemistry students in Nkrankwanta Senior High Technical School. Two intact classrooms were used for the study. The control group consisted of forty five (45) second year science students and the experimental group was equally Forty (40) second year Agricultural science students‘. Tests (Chemistry Achievement Test) and questionnaire with reliability coefficient of 0.80 were the instruments used for data gathering. Chemistry achievement pre-test was administered to both experimental and control groups. An intervention was carried out for the experimental group after which chemistry achievement post-test was also administered to both groups. Descriptive statistics such as percentages, mean , standard deviation and inferential statistics independent samples t-test, and paired samples t-test were used in analysing the collected data to answer four research questions and two null hypotheses, which were tested at 0.05 level of significance. The t-test results for control and experimental groups indicated that there was a statistically significance difference between students Post-test scores of both Control group exposed to Traditional method and Experimental group exposed to Problem-Based Learning approach. Also, the inferential statistics carried on the pre-test and posttest scores of students‘ in the experimental group exposed to Problem-Based Learning approach revealed there was no statistically significant difference between the cognitive achievement of male and female students‘ in chemistry. The study therefore recommends the need for inclusion of problem-based learning approach in the Senior High School chemistry syllabus and textbooks as this can result in significantly higher students‘ cognitive achievement in chemistry concepts such as redox reaction and acid-base concepts than the conventional approach (traditional learning approach).