For example, I have a set of numbers (say 0 to 10) that are presented to 100 subjects. Each subject is asked whether the number is a small or a large number.
The results are that 100 people think zero is a small number, 70 people think one is a small number, etc.
Now I use a certain distribution, say, exponential to estimate the parameter of the distribution based on these data.
I assume people give subjective opinions and that most of them think 0 is a small number so it may be assumed that the degree of truth of zero being a small number is 1.
Finally, by multiplying the exponential probability density function (PDF) by a constant, I can scale the (PDF) such that the peak of it hits one and making it a membership function.
Does this sound right?