Creative Speculation

same as formulating theories on how something works and then being able to test it, repeatedly.

That, to me, is the greatest difficulty in treating anecdotal evidence as hard data. Each individual is a separate observation and has a myriad of variables, all of which will change over time. And then we need to get most of the data by watching and questioning the subject which is not reproducible or stringent.

In the hard sciences these theories can be retested and the subjects are usually pretty hard objects that react in some known way over time and environment.