The goal of forecasting is not to predict the future but to tell you what you need to know to take meaningful action in the present.

I assume this is a limited-time offer; soon the article will disappear behind the paywall.

Prediction is possible only in a world in which events are preordained and no amount of action in the present can influence future outcomes. That world is the stuff of myth and superstition.

Here are the rules:

Rule 1: Define a Cone of Uncertainty
Rule 2: Look for the S Curve
Rule 3: Embrace the Things That Don’t Fit
Rule 4: Hold Strong Opinions Weakly
Rule 5: Look Back Twice as Far as You Look Forward
Rule 6: Know When Not to Make a Forecast

Paul Saffo, on Six Rules for Effective Forecasting | HBR