In fuzzification, we converted the crisp values of our input to fuzzy degree of membership values for our linguistic variable. In defuzzification, we need to convert the degree of membership values for our output variable to its crisp value.
Let us superimpose the membership function on top of the above decision plot. We have assumed a triangular membership function here. You can read more about triangular membership function and their importance in the paper why triangular memebership functions? http://www.sciencedirect.com/science/article/pii/0165011494900035
Decision plot with superimposed membership function:
The most ...