Poolology is a system that helps develop a good eye for fractional style aiming. If a player needs to use it on every shot then that's fine, but it's most accurate on shots that are 1/4 hit or thicker. Here's a good example of when the system might come in handy for even a well experienced player... center table back cuts:
Any ob located on the blue line can be sent into the corner pocket by aiming at whatever aim point indicated by the centerline of the balls in reference to the end rail diamonds. This is a 1/2 ball shot, or a #4 aim.