Carry out investigations
Preparation is key. Students should collect and organize all materials, supplies, and equipment needed to perform their experiment. This includes any tables or charts needed for data collection.
It’s important that students do a preliminary run so they may reflect and revise their methods if necessary. They can also show the preliminary data to a mentor or teacher for feedback. Students should document all revisions to the procedure methods or materials. This is a normal part of developing successful investigative procedures.
Whenever possible, students should run the trials or replicates simultaneously. For example, if they are growing plants, they can put five identical plants (or seeds) in five separate pots as their five replicates in one test group. Other treatment groups or the control group would have replicates in the same manner. If all plants are growing simultaneously, they will all be subject to the same conditions, creating more consistent data.
In experiments that involve surveys of people, multiple trials are not necessary. Instead, the reliability of the survey will depend on the number of people responding to the survey. The ideal sample size depends on what the student is evaluating, but the more respondents the better (SARSEF recommends at least 30 responses to surveys).