2. Literature review
2.1. Scientific investigation in chemistry
Investigation is just one type of activity in science. The central feature of an investigation is that something
is changed and the effect that it has on something else is measured. Scientific investigation is the process thatinvolves students in: 1) forming a hypothesis including identifying variables and selecting a variable to investigate,
2) planning and carrying out the investigation, 3) recording, presenting, and interpreting the results, 4) evaluating thehypothesis in relation to the results of the investigation, 5) drawing an inference from the results, and 6)
communicating the findings, as shown in Figure 1 (Bevins, et. al., 2001). During the investigation process, students
have to make the following decisions: deciding on key variables to change and to measure, asking an investigating
question, predicting or hypothesizing the investigation, planning and designing the test, recording results, finding
patterns in results, making sense of patterns in results, and evaluating the reliability of the results (Windale &
Puangmanee, 2008).
Figure 1. The whole process of scientific investigation