Type of Research Research Design Population and Sampling

Muhammad isha Juarsa THE EFFECT OF ROLE PLAY LEARNING METHOD TO STUDENT’S ACHIEVEMENT IN PHOTOSYNTHESIS TOPIC Universitas Pendidikan Indonesia | repository.upi.edu | perpustakaan.upi.edu

CHAPTER III RESEARCH METHOD

A. Type of Research

This research is quantitative method, using experimental research. By considering the condition of each class in this Junior high school, which each class has different capabilities of student. For example, class VIII-A has a better academic achievement and english capability rather than VIII-B and VIII-C, so researcher would like to choose pre-experimental research especially one group pretest posttest study which only use one class so that this research would be on target and representative.

B. Research Design

One group pretest – posttest study design will be used in this research. The one-group pretest-posttest design is a research design where one group of participants is pretested on the dependent variable and then posttested after the treatment condition has been administered. This is a better design than the one- group posttest-only design because it at least includes a pretest, that indicates how the participants did prior to administration of the treatment condition. The design could be seen clearly as the diagram shown below: Key: O 1 = Pretest O 2 = Posttest X = Treatment One Group Pretest – Posttest Study O 1 X O 2 Muhammad isha Juarsa THE EFFECT OF ROLE PLAY LEARNING METHOD TO STUDENT’S ACHIEVEMENT IN PHOTOSYNTHESIS TOPIC Universitas Pendidikan Indonesia | repository.upi.edu | perpustakaan.upi.edu Figure 3.1 : Diagram of one group pretest – posttest study As the name suggest, one group pretest posttest comprises pretest and posttest as its main data. In this design, the effect is taken to be the difference between the pretest and posttest scores. It does not control for potentially confounding extraneous variables such as history, maturation, testing, instrumentation, and regression artifacts, so it is still difficult to identify the effect of the treatment condition.

C. Population and Sampling

Population of students is taken from one of the school in Bandung. Meanwhile the sample of students is taken in grade VIII-A since photosynthesis chapter is learnes in this grade. The class itself is taken by purposive sampling.

D. Research Variable