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 a box with a leaf in below. The leaf comes from one type of made-up tree. On the right of the leaf are two boxes with the names of two trees on them. Each time you see a new leaf, you must decide which tree the leaf comes from. At first you will have to guess. With practise, though, you will hopefully learn by trial and error until you can click correctly on the tree name for the leaves every time.
Now click on the box with the tree name that you think the leaf comes from. 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 leaf.
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 fifteen trials in a row right before you can start on the next block of the experiment.
There are six blocks of trials altogether. Different pairs of made-up tree names are used in each of the blocks, but the instructions for each block are the same. The first block of trials is easy. It is designed to help you understand the instructions. Now try to guess which tree the leaf comes from.
If you are not connected to the net or something goes wrong, the experiment will abort.