Hypothesis Testing II: The t test
The t test looks at the mean and variance of a sample of measurements, where the null hypothesis is that the sample is drawn from a distribution with mean ?.
The test looks at the difference between the observed and expected means, scaled by the variance of the data, and tells us how likely one is to get a sample of that mean and variance assuming that the sample is drawn from a normal distribution with mean ?.
To apply the t test to collocations, we think of the text corpus as a long sequence of N bigrams.