Introducing students to experimental design skills
The results of an earlier empirical research study on modifying ‘step-by-step’ instructions to practical activities requiring one or more steps of the experiments to be designed by students initiated a longitudinal study to investigate the effectiveness of the approach for younger students and over a period of time. The longitudinal study that followed took the form of a four year research project that began in September 2016. Over 900 students have been involved. All were 12–13 years old in the beginning of the study. Each year they spend six lessons carrying out practical activities using worksheets we provide. This paper reports the findings of the first year, when the participating classes were allocated to one of three groups. Group 1 was the control group. Students simply followed the step-by-step instructions. Groups 2 and 3 were experimental groups. Group 2 students not only followed the same instructions, but also had to complete experimental design tasks on paper. Group 3 students followed the same instructions, but one or more steps were incomplete and students were required to design these steps. The impact of the intervention on the students’ experimental design skills, disciplinary content knowledge and attitude toward chemistry is measured by structured tests. After the first school year of the project it was clear that the type of instruction only had a weak significant positive effect on the results of the Group 2 students’ disciplinary content knowledge. No significant effect of the intervention could be detected on the changes in the students’ grades and attitudes toward the subject, which only seemed to depend on the ranking of their schools. This paper provides the interesting details of the results of the first year (pilot) of the research and discusses changes to the approach that have been made for the remaining three years of the project.