Fuzzy logic
Fuzzy logic is a subset of AI that takes an open, imprecise spectrum of data (imprecise input) and processes multiple values in a way that produces output that includes a range of intermediate possibilities between YES and NO (e.g., certainly yes, possibly yes, cannot say, possibly no, certainly no).
Fuzzy Logic systems produce definite output in response to incomplete, ambiguous, distorted, or inaccurate (fuzzy) input, simulating human decision making more closely than conventional yes/no logic.
Fuzzy logic can be implemented in hardware, software, or a combination of both.
Sources: