Editing Pie chart (section)

{{short description|Circular statistical graph that illustrates numerical proportion}}
{{Distinguish|Circle graph}}
{{About||the South Korean music chart|Circle Chart|Information on generating pie charts in Wikipedia|:Wikipedia:Graphs and charts|and|:Template:Pie chart}}

[[Image:English dialects1997.svg|thumb|right|Pie chart of populations of [[English language|English]] native speakers]]
A '''pie chart''' (or a '''circle chart''') is a circular [[Statistical graphics|statistical graphic]] which is divided into slices to illustrate numerical proportion. In a pie chart, the [[arc length]] of each slice (and consequently its [[central angle]] and [[area]]) is [[Proportionality (mathematics)|proportional]] to the quantity it represents. While it is named for its resemblance to a [[pie]] which has been sliced, there are variations on the way it can be presented. The earliest known pie chart is generally credited to [[William Playfair]]'s ''Statistical Breviary'' of 1801.<ref name="Spence2005">Spence (2005)</ref><ref name="Tufte, p. 44">Tufte, p. 44</ref>

Pie charts are very widely used in the business world and the mass media.<ref name="Cleveland">Cleveland, p. 262</ref> However, they have been criticized,<ref name="Wilkinson">Wilkinson, p. 23.</ref> and many experts recommend avoiding them,<ref name="tufte">Tufte, p. 178.</ref><ref name="vanbelle">van Belle, p. 160–162.</ref><ref name="sfew">Stephen Few. [http://www.perceptualedge.com/articles/08-21-07.pdf "Save the Pies for Dessert"], August 2007, Retrieved 2010-02-02</ref><ref name="fenton">Steve Fenton [http://www.stevefenton.co.uk/Content/Pie-Charts-Are-Bad/ "Pie Charts Are Bad"]</ref> as research has shown it is more difficult to make simple comparisons such as the size of different sections of a given pie chart, or to compare data across different pie charts. Some research has shown pie charts perform well for comparing complex combinations of sections (e.g., "A + B vs. C + D").<ref name="spence91" /> Commonly recommended alternatives to pie charts in most cases include [[bar chart]]s, [[box plot]]s, and [[dot plot (statistics)|dot plot]]s.