This type of hypothesis is one which predicts the direction of the difference or in terms of correlational analysis predicts either a positive or negative correlation.    A directional hypothesis is also called a one tailed hypothesis. 

A non directional hypothesis on the other hand predicts a difference between two variables but not the direction or in terms of correlational analysis it does not predict either a positive or negative correlation.   A non directional hypothesis is also called a two tailed hypothesis.

Contributers

Last Updated on 3 March 2006