Normal Curve

Synonyms

Bell curve; Frequency curve; Gaussian distribution; Laplace-Gaussian curve; Natural distribution; Normal distribution; Probability density function

Definition

The normal curve is a theoretical, bell-shaped distribution thought to describe the frequency of occurrence of many natural phenomena, including such varied things as height, blood pressure, reaction time, and scores on cognitive tests. Further, it serves as a mathematical model for describing random events in probability and statistics. http://mathworld.wolfram.com/classroom/classes/ProbabilityandStatistics.html, retrieved on 8/29/08

Characteristics

History

Mathematician Abraham de Moivre published an article on the curve in 1733 as a way to approximate the binomial distribution. This account latter appeared in his book on probability theory, The Doctrine of Chances (1738). Another Frenchman, Pierre-Simon Laplace, made use of the curve in describing the distribution of random errors (1783), and