An experiment is performed to compare two different ways of presenting the instructions for operating a photocopying machine. Type A relies heavily on the use of diagrams. Type B uses verbal descriptions. It is hypothesised that the Type A instructions will be both more effective and easier to remember. The 20 participants, none of whom have used a photocopier before, are divided equally into two groups; one is presented with Type A instructions, the other with Type B instructions. The participants are allowed to study the instructions for 4 minutes. They then have to make a photocopy and the time taken to do this is recorded. One week later the participants return and make another copy and are again timed.