So, the key question now is how to determine whether the observed result is surprising under the assumption that infants have no real preference. (We will call this assumption of no genuine preference the null hypothesis.)
To help us evaluate whether these results are convincing of a genuine preference by infants in general rather than just a fluke outcome, we can simulate the choices of the infants. A simulation is an artifical representation of a random process used to study the process's long-term properties.
To answer this question, we will replicate the infants’ selection process over and over, assuming that the infants have no genuine preference and each was essentially flipping a coin in making their choices (i.e., knowing the null hypothesis to be true). In other words, we’ll simulate the process of 16 hypothetical infants making their selections by random chance (coin flip), and we’ll see how many of them choose the helper toy. Then we’ll do this again and again, over and over. Every time we’ll see how many of the 16 infants choose the helper. Once we’ve repeated this process a large number of times, we’ll have a pretty good sense for whether 14 of 16 is very surprising, or somewhat surprising, or not so surprising under the null hypothesis.
Now the practical question is, how do we simulate this selection at random (with no genuine preference)? One answer is to go back to the coin flipping analogy. Let’s literally flip a coin for each of the 16 hypothetical infants: heads will mean to choose the helper, tails to choose the hinderer.
