Eric was fascinated by the latest episode of “Who Done It?”, a mystery thriller he had watched on tape-delay last night. It seems the key to solving the mystery was the ability of Sam Shovel, the...

Eric was fascinated by the latest episode of “Who Done It?”, a mystery thriller he had watched on tape-delay last night. It seems the key to solving the mystery was the ability of Sam Shovel, the detective, to match patterns in various handwriting samples. Eric decided to write a simple program to mimic Sam’s pattern-matching behavior. The first thing Eric did was to create a set of 26 “perfect” printed letters on 15 × 21 grids. These templates would then be compared to actual printing samples, one after the other, to deduce the actual printed characters. His first attempt at writing this program was a total flop! He soon had discovered that none of the actual printed characters was an exact match for his “perfect” characters; he had not recognized any part of the suspect’s message.