In STATISTICS, a value representative of a whole group of numbers, such as one of the MEASURES OF CENTRAL TENDENCY (MEAN. MEDIAN and MODE ). See also GROUP NORM andSOCIAL NORM.

A technique used in studies of learning where words are presented to the subject in pairs and afterwards he is given the first word of each pair and asked to recall the second.

In PSYCHOANALYSIS, the loss of love from a valued external object.

Abbreviation for NEED FOR ACHIEVEMENT.

Statistical methods that may be used when the data do not conform to a NORMAL DISTRIBUTION, i.e. most data in studies of human BEHAVIOUR.

The physiology of the nervous system.

Producing a greater effort than is needed to overcome a difficulty or resolve a defect. Often used in connection with attempts to overcome anINFERIORITY COMPLEX.

The EVOLUTION and development of an individual organism. Contrast with PHYLOGENY.

A term used in SOCIOLOGY to denote a person of status within a given group whose opinions are highly thought of and who can therefore influence the opinions of other members of the group. See TWO-STEP FLOW OF COMMUNICATION.

One of the cues used in DEPTH PERCEPTION : near objects seem to move faster than objects that are further away.