Here are a couple of Simile models which try and show that statistical inference is largely about comparing data against the output of a null model. In statistical text books the null model is not usually mentioned explicitly. Instead the null hypothesis, and the the assmptions of a test are presented, but the null hypothesis and the assumptions are really specifying an underlying null model.
These two Simile models look at a t-test (actually a paired t-test) and a one-way ANOVA. They use the same data set, which comprises two samples, each with 20 observations.