Statistical graphics

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Statistics and data analysis procedures can broadly be split into two parts: quantitative techniques and graphical techniques. Quantitative techniques are the set of statistical procedures that yield numeric or tabular output. Examples of quantitative techniques include hypothesis testing, analysis of variance, point estimation, confidence intervals, and least squares regression. These and similar techniques are all valuable and are mainstream in terms of classical analysis.

On the other hand, there is a large collection of statistical tools that we generally refer to as graphical techniques. These include: scatter plots, histograms, probability plots, residual plots, box plots, block plots, and biplots. Exploratory data analysis (EDA) relies heavily on these and similar graphical techniques. Graphical procedures are not just tools used in an EDA context; such graphical tools are the shortest path to gaining insight into a data set in terms of testing assumptions, model selection and statistical model validation, estimator selection, relationship identification, factor effect determination, and outlier detection. In addition, good statistical graphics can provide a convincing means of communicating the underlying message that is present in the data to others.

Famous graphics were designed by William Playfair who published what could be called the first pie chart and the well known diagram that depicts the evolution of England's imports and exports. Other notorious graph makers were Florence Nightingale who used statistical graphics to persuade the British Government to improve army hygiene, John Snow (physician) who plotted deaths from cholera in London in 1854 to detect the source of the disease, and Charles Joseph Minard who designed a large portfolio of maps of which the one depicting Napoleon's campaign in Russia is the best known. A special type of statistical graphic are the so called isotypes. These are graphical tools designed by Otto Neurath with the specific purpose of achieving changes in society through visual education of the masses.

If one is not using statistical graphics, then one is forfeiting insight into one or more aspects of the underlying structure of the data.

[edit] See also

• List of graphical methods
• Visual inspection

[edit] Bibliography

• Cleveland, W.S. (1993). Visualizing Data. Summit, NJ, USA: Hobart Press. ISBN 0-9634884-0-6. 
• Cleveland, W.S. (1994). The Elements of Graphing Data. Summit, NJ, USA: Hobart Press. ISBN 0-9634884-1-4. 
• Lewi, Paul J. (2006). Speaking of Graphics. 
• Tufte, Edward R. [1983] (2001). The Visual Display of Quantitative Information, 2nd Edition, Cheshire, CT, USA: Graphics Press. ISBN 0-9613921-4-2. 
• Tufte, Edward R. [1990] (1992). Envisioning Information. Cheshire, CT, USA: Graphics Press. ISBN 0-961-39211-8. 

[edit] External links

• Alphabetic gallery of graphical techniques
• DataScope a website devoted to data visualization and statistical graphics

v • d • e Visualization Related fields Computer graphics • Computer science • Graphic design • Graphic image development • Human-computer interaction • Informatics • Visual communication See also Data mining • Gestalt psychology • Graph theory • Graphic organizer • Illustration • Imaging • Information graphic • Information graphic designers • Interactive visualization • List of graphical methods • List of graphing software • Representation (arts) • Representation (psychology) • Rendering (computer graphics) • Statistical graphics

This article incorporates text from a public domain publication of the National Institute of Standards and Technology, a U.S. government agency.