Two heads are better than one. How about more?

I like hiking a lot, especially with a few good friends of mine. But when the scenery is wild, or when the weather conditions are harsh, it is not uncommon to lose trail, or  at least – be in doubt whether we are going the right way. In these situations we discuss with each other, consulting as well a map and compass. And even if none of us is certain about the right path we need to take on an overgrown crossroad, we usually manage to reach the mountain hut as we planned.

A common wisdom says that two heads are better than one. In this article we will investigate empirical basis for this claim. Additionally, we will look at frameworks quantifying performance in simple tasks, trying to answer how does ‘doing better’ scale with the number of participants, and their skills.