To begin, please fill in the details box below (this may take a little while to load in) and click on submit.
Your computer should then download a java programme. It is only 29K long but it will take a few moments to load in, depending on the speed of your connection.
When the programme has loaded you should see two boxes below. In each box are two drawings of a leaf from one of two classes of differently shaped leaves. We have chosen one class as the 'good' leaf class. For each set of leaves that you see, you must decide which pair of leaves is from the good leaf class. At first you will have to guess. With practise, though, you will hopefully learn by trial and error until you can do the task accurately.
Now click on the box with the pair of leaves that you think come from the GOOD class. As soon as you have done this, a tick or a cross appears to say whether your decision was right or wrong. Now click again to get the next set of leaves.
The line of ticks at the bottom of the screen shows how many trials you have got right in a row. If you get one wrong, a cross will appear, and you will go back to having no ticks. You have to get ten trials in a row right before you can start on the next experiment.
There are five experiments altogether. Different leaf classes are used in each of the experiments, but the instructions for each experiment are the same. The first experiment is easy. It is designed to help you understand the instructions. Try now to guess which of the pair of leaves below are from the good class.
If you are not connected to the net or something goes wrong, the experiment will abort.