The level of cognitive ability attained in the third of PIAGET’S of CHILD DEVELOPMENT from about 7 to 11 years of age. At this stage children are supposed to be capable of logical thinking about concrete objects, while abstract thinking is still beyond them. The most important achievement of this stage is the idea of CONSERVATION.

A statistic (R) that measures the extent to which two VARIABLES are correlated. It can range from zero correlation to perfect correlation (1.00), where the variables are always associated in the same way, or perfect negative correlation (-1.00), where the variables are always associated but in different ways.

Large, slow brain waves occurring about three occouring a second. Found only in deep sleep.

STATISTICS that summarise or describe a set of measurements, e.g. MEASURES OF CENTRALTENDENCY.

Compare with INFERENTIAL STATISTICS.

The outline or boundary of an object which is essential to its PERCEPTION.

The tendency among humans and animals to explore their environment for its own sake.

A DELIRIUM suffered by chronic alcoholics after withdrawal of alcohol. A classic WITHDRAWAL SYMPTOM.

The analysis of material in PSYCHOLOGY and in SOCIAL SCIENCE to see what categories or themes emerge, or the analysis of material by prearranged theme or categories to test a HYPOTHESIS or make a diagnosis.

In PSYCHOANALYSIS, a part of the SUPEREGO that represents an IDENTIFICATION with parents or parent figures who are admired and loved.

A technique of learning in which the lessons or periods of practice are spread out as widely as the available time permits. A much more effective method of learning than SPACED PRACTICE, with which it is usually contrasted.