Sometimes, one comes across some models which attempt to predict the behavior of a system based on past data. In order to come up with such models, the “outliers”, or data which deviate very far from the mean, are often left out.

However, it could so happen that in many systems, the entire behavior may be totally determined by the outliers. Also, it is difficult to choose an outlier and to understand how it could impact the system. So, much of the predictive modeling and “forecasting” turns out to be useless or even dangerous because they tend to mislead the human brain.

Predicting the weather

Weather predictions for the next few days are known to be pretty accurate. However as the days turn to weeks, the accuracy goes down dramatically.

It seems that to predict accurately, one needs to know and understand the rules of the game. As things get complex, take the climate for example, the rules are more difficult to understand. So, it becomes hard to pinpoint how climate will change in the future. However, we need to not mess with nature and risk causing any more global warming. This could be done as a matter of applying the precautionary principle.