Good decisions are based on good data. The most intelligent people and the most sophisticated computers systems in the world get it wrong from time to time. People like to use the term "Facts" and "Supporting Data". But what if your truth isn't based on reality? We all want to make good decisions and seek out relevant data in order to obtain "Truth" and derive a sincere opinion. However, if our data isn't proper, or granular enough to make logical decisions, we find ourselves being sincerely wrong, and supported by what we believe to be data.
The question becomes, how do we obtain the proper information and enough of it, in order to make good decisions? Ideally, we would search out an expert in the field and question them. Learn from others experiences in similar situations. Look at historical data that has known outcomes and study it.