Representations III

• It is good if every syntactically legal bit string represents a well-defined hypothesis.
• So 111 10 11 represents a rule whose postcondition does not constrain the target PlayTennis. To avoid this allocate just one bit to PlayTennis to indicate Yes or No, or alter the genetic operators so they explicitly avoid constructing such bit strings, or assign them a very low fitness (only works if there are only a few!!!)
• Some GAs represent hypothesis as symbolic descriptions rather than bit strings (more later).