Designing an experiment

Your task is to design and run an experiment to investigate the relationship between two variables. It is up to you to design the experiment but you must produce a specific outcome so keep this in mind and make it your starting point. Things to consider.

You will perform the experiment in your prac group but your report will be submitted individually. The report must follow the guideline given in the document ‘Student designed Investigation’. You should also read carefully through the Example report prepared for you which will give you an idea of what is expected for this task. Finally read Appendix 1: Investigations: a helping hand on p.244 of your text.

Your work will be graded using the Yr 12 Extended Practical Investigation (EPI) rubric. This is to get you used to the expectations and requirements for your EPI. Do not fear, obviously we are very aware that this is your first attempt at such a task, you will get many.

Designing your experiment:

Things to consider.

1. What is my final outcome requirement?

2. What is the physics involved?

3. What are my controlled variables? (What things will I need to measure to achieve this outcome?)

4. What are my extraneous variables? (What are the things that may effect my experiment that I can't control but I may be able to limit?)

5. What are my parameters? (What will be the range of my data? How many different tests? How many repeats? How long to I have??)

So the first thing you need to discuss in your group is what things can you measure? What things will vary? Write a list of all the things you could change in this situation under this heading in your workbook.

You now need to decide what you will investigate. You must choose one variable to test and then hold the others constant. This variable must give you the data you need to solve your problem.

Circle the variable you will vary in your list.

Now you have a variable to focus on you must create a question or Hypothesis and state your Aim

Write your Hypothesis and Aim into your workbook

The next thing to decide are the parameters and limits. This involves thinking about how much time you have, how much data you want to collect and how big the investigation is going to be. In a school setting you are often constrained with access to equipment and time. For this task I would recommend not collect much more than 50 data points. Write out how many variable points you expect to test and how many repeats you can do in your time limit of 40 minutes.