The ETPG A-Z complements many specialist dictionaries and glossaries which provide scientific definitions of technical terms used in psychology and testing.

Our definitions use simple language except where further technical terms are unavoidable. In places we’ve included non-technical terms to examine their implications for testing.


We’ve introduced certain statistical concepts, tried to explain their implications and why they’re important, but left out any detailed statistical explanation. This is not to downplay the significance of statistics in this area but we believe there are better ways of explaining and learning these techniques .


If you want more information do ring us. Also ring us if you can’t find a term in our A-Z.  We’ve tried to be selective and we may have missed some words out.