Evoked potential is the term for a way of directly measuring general intelligence. This works using a rather simple procedure. First you wire your subject up to an electroencephalograph (EEG) machine. Then you either flash a bright light into their eyes, or produce a loud click next to their ears. Immediately after doing this, you will find that a spike appears in the brain waves. This has been "evoked" by the stimulus, hence the name. The time between the stimulus and the response is directly related to "g", your subject's general I.Q., the higher the I.Q., the shorter the gap between stimulus and response. This measure is about 70% of your score in an I.Q. test, and is analagous to your computer's clock speed.