Poisson distribution

a discrete distribution that generates the probability of occurrence of rare events that are randomly distributed in time or space. It is a type of theoretical distribution. Count variables, such as the number of aggressive acts observed on a playground or the number of times a person attempts to stop smoking, take this form. When a variable is distributed in this way, a researcher needs to consider specialized statistical models. [Siméon D. Poisson (1781–1840), French mathematician]

Browse dictionary by letter

a b c d e f g h i j k l m n o p q r s t u v w x y z

Psychology term of the day

December 19th 2024

verbal deprivation hypothesis

the hypothesis that children who are denied regular experience of an elaborated code of language—that is, a more formal use of language involving complex constructions and an unpredictable vocabulary—may develop an educational and even cognitive deficit. The concept is controversial as it has been associated with the view that nonstandard or vernacular forms of a language (e.g., Black English) are inherently inferior. The idea that nonstandard forms inhibit higher level cognitive processes (e.g., abstract reasoning) is now discredited, but concerns remain that lack of early exposure to the more formal codes of a language appears to correlate with educational underachievement. [proposed in 1973 by British sociologist Basil Bernstein (1924–2000)]