Practical 8 Introduction to Designing an Experiment
Introduction
This practical is used to introduce students to the idea of making up a research question and how to write up a full practical report. The area of research is a rubber bung tied to the end of an elastic string, students are given an example of a research question but are supposed to make up their own, if they find this too difficult they can be given one or use the example. The chosen research questions do not necessarily lead to a linear relationship so it is not appropriate to plot a linear best fit or steepest and least steep lines, for this reason I do not use design experiments to assess DPP.
Assessment
Since a lot of help is given in the worksheet this practical is not used to assess any of the criteria however I do mark the reports and give feedback to the students.
Feedback is given on the following criteria
Design
Students should give a clear research question and list the variables. It is a good idea to start the report by introducing the area of research. A complete description of the method should include a diagram and list of apparatus. The student should clearly state how the variables were measured and what they did to ensure the controlled variables did not change. Measurements should be made over a reasonable range, each measurement should be repeated about 5 times.
DCP
Tables should be constructed as in the previous practicals with appropriate headings and consistent decimal places. Graphs should be correctly labeled and include error bars, best fit lines or curves. Where curves are plotted they should be consistent with the hypothesis.
CE
Students should comment on their graph and state if it is consistent with their hypothesis. Weaknesses in the method should be mentioned and ways these could be addressed noted.
Click here for a sample worksheet