If you become a predictor, and make a prediction that is justified by fair use of the tricks of the trade, you are bound to encounter a heckler who wil assail the fallibility of each of your datums.

Your datums are things you read, things people said, personality assessments, things that have happened,  things that appear to be happening,  trends, and fact-fences. Taken individually, each of these datums is of low quality. This is to be expected of open sources, save the occasional assassination where the body is clearly on display.

So how do you answer your heckler? The answer lies in the realm of both pure and applied mathematics:

1. The Central Limit Theorem.

2. Techniques of data fusion.

Unless you have a particular interest, there is no need to delve deeper. A confident look, and a “read it and then we’ll talk” should suffice. You’ll probably never hear from the guy.