Randomness and Probability

Abstract

Suppose that, for some reason, we want to know how many times a secondlanguage learner makes errors in a writing task; to be more specific, let’s assume we will only count verb inflection errors. The dependent variable (here, the number of inflection errors) is random in the sense that we don’t know in advance exactly what its value will be each time we assign a writing task to our subject. The starting point for us is the question: What’s the pattern of variability (assuming there is any) in the dependent variable?