Expected value

From Lesswrongwiki
Revision as of 02:23, 14 October 2016 by Ete (talk | contribs) (added links to Arbital)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search
Smallwikipedialogo.png
Wikipedia has an article about
Arbital has an article about

The expected value or expectation is the (weighted) average of all the possible outcomes of an event, weighed by their probability. For example, when you roll a die, the expected value is (1+2+3+4+5+6)/6 = 3.5.

(Since a die doesn't even have a face that says 3.5, this illustrates that very often, the "expected value" isn't a value you actually expect.)

See also

External links