Estimating Probability Functions
What is the probability that sentence “The cow chewed its cud” will be uttered? Unknown ==> P must be estimated from a sample of data.
An important measure for estimating P is the relative frequency of the outcome, i.e., the proportion of times a certain outcome occurs.
Assuming that certain aspects of language can be modeled by one of the well-known distribution is called using a parametric approach.
If no such assumption can be made, we must use a non-parametric approach.