Research: A systematic investigation to establish facts or principles or to collect information on a subject.
Generalisation: The process of formulating general concepts by abstracting common properties of instances.
Hypotheses: Propositions made as a basis for reasoning, without the assumption of its truth.
Reliability: The consistency of a research study or measuring test.
Validity: The extent to which a concept, conclusion or measurement is well-founded and likely corresponds accurately to the real world.
Sampling: The process of selecting a representative group from the population under study.