Comparing the effects of mnemonic, prior knowledge and modified lecture-based instructional strategies on students’ learning outcomes of ion-identification in Accra girls’ senior high school

Abstract

The type of instructional strategies adopted by students and teachers affect learners’ educational outcomes such as students’test scores or attitude to the topic after instruction, whether favourably or otherwise. The purpose of this study was to determine the most effective teaching method for the instruction of ion identification, during ion-qualitative analysis in Accra Girls’ Senior School by adopting the pretest posttest control true experimental design. Twelve students each from a randomly selected intact class were randomly assigned to three independent groups. Treatment lasted for two weeks. Instruments used were achievement test, self-administered questionnaire (Cronbach reliability=0.84) and an interview schedule. Three hypotheses were tested at 0.05 level of significance and, data analysed using the one way analysis of covariance followed by Bonferroni post hoc pairwise comparison test .The participants were relatively young (M = 17.33, SD = 0.89) and residential status split between day (50%) and boarding (50%).The respective mean achievement scores for MBIS, RPKBIS and MLM groups, controlling for covariate were 27.69 (SD=0.61), 20.78 (SD=0.60) and 16.37 (SD=0.62). Pairwise comparison indicated statistically significant contributions by all three levels of the independent variable. On all five measures of attitude, students in the mnemonic group scored highest after treatment, with that of prior knowledge trailing. All twelve students in the mnemonic group reported an improved performance due to option to select one’s own mnemonic type for analysis. All three null hypotheses were thus rejected since differences in means were statistically significant (F(2, 32) = 67.39, P < 0.05) . Overall, the study revealed that learners’ test scores and attitude to ion qualitative analysis improved by the largest margin when mnemonic-based instructional method was adopted compared with the prior-knowledge or modified lecture method of instruction. It is recommended that curriculum designers include mnemonics for the ion analysis and students should be encouraged to create and use their own mnemonics especially acronyms for the ion qualitative analysis and periodically study it using “doing practice problems” since these ranked first among other strategies for effectiveness.