Glossary
Law of a phenomenon

Sample

A "sample" is a set of values taken from a parent population (the notion of representativeness is still the subject of debate).

Sample size

Number of values contained in a sample.

Parent population

The "parent population" is the totality of values that a random phenomenon can produce, i.e. the series of values that would be obtained if an infinite number of observations were made. In general, the parent population can never be known, but this is not always the case. For example, the collection of a class's marks for an assignment represents a finite parent population. All its values are known.