3. Study Design and Sample
The research study adopted a pre-test, post-test quasi-experimental design in which three public senior secondary schools were randomly selected in Ife Central Local Government Area of Osun State, Nigeria. Intact class of Chemistry students in Senior Secondary Class two (SSII) were selected for the study. A total of one hundred and fifty six (156) students formed the sample for the study. The age range of the students was between 13 and 17years.Selected sample were randomly assigned to the treatment groups. The treatment involves the use of concept mapping strategies (Spider, Flowchart and Hierarchy) to teach the mole concept and related concepts that are associated with stoichiometry in Chemistry. A pre-test was used to determine the entry level of the subjects. The treatment was then carried out for five weeks after which a post-test followed to determine the effects of the treatments.