hypothesis

Definition 1

General: Supposition or explanation (theory) that is provisionally accepted in order to interpret certain events or phenomenon, and to provide guidance for further investigation. An hypothesis may be proven correct or wrong, and must be capable of refutation. If it remains unrefuted by facts, it is said to be verified or corroborated (but never 'right').

Definition 2

Statistics: Assumption about certain characteristics (parameters) of a population (such as its mean). If it specifies values for every parameter of a population, it is called a simple hypothesis; if not, a composite hypothesis. If it attempts to nullify the difference between two sample means (by suggesting that the difference is of no statistical significance), it is called a null hypothesis.