Step 4 - Planning the experiment
|Designing the experiment|
|Listing what you need||Describe how you will use them. Make a diagram if you want.|
30 cress seeds cotton wool
3 dishes cling film
The pupils now plan the experimental procedure. It is very important to stress that only one of the variables can be changed during the experiment. As a result the variable being measured will, presumably, change. All other variables must be kept constant to ensure a fair test.