A good decision is based on...

"A good decision is based on knowledge and not on numbers."
- Plato


You would hope that when a person makes a decision they actually have knowledge about what they are deciding; most people would agree that's ideal.

Let's just say two hungry people are walking down the street where they are confronted with two choices: fast food or health food. The first person pulls out their Blackberry and promptly searches the internet for data comparing fast food to health food (prices, health differences, etc.). They find that health food can be more expensive but has a health difference far greater than the price difference, and so they choose health food. The next day his/her friend is surprised they chose health food and asks why he/she made that decision. "I can't remember, but I looked it up."
The second person must also decide fast food or health food. This person walks right into the health food store without much contemplation. Why? Because the second person knew why health food is a better choice.

One person made a decision based on numbers and the other based on knowledge. The result was the same (and will always be the same), so, although it may not be ideal, a decision based on numbers can be as good as one based on knowledge.