A small multiple (sometimes called trellis chart, lattice chart, grid chart, or panel chart) is a series of similar

graph Graph may refer to: Mathematics *Graph (discrete mathematics), a structure made of vertices and edges **Graph theory, the study of such graphs and their properties *Graph (topology), a topological space resembling a graph in the sense of discre ...

s or

chart A chart (sometimes known as a graph) is a graphical representation for data visualization, in which "the data is represented by symbols, such as bars in a bar chart, lines in a line chart, or slices in a pie chart". A chart can represent tabu ...

s using the same scale and axes, allowing them to be easily compared. It uses multiple views to show different partitions of a

dataset A data set (or dataset) is a collection of data. In the case of tabular data, a data set corresponds to one or more database tables, where every column of a table represents a particular variable, and each row corresponds to a given record of the ...

. The term was popularized by

Edward Tufte Edward Rolf Tufte (; born March 14, 1942), sometimes known as "ET",. is an American statistician and professor emeritus of political science, statistics, and computer science at Yale University. He is noted for his writings on information design ...

. According to Tufte,

Modern example

In the example, the departmental salary expense is charted by month with a dashed line indicating the average for each department. The scales on each panel are different to emphasize the relative change over time compared to the range. Standardizing the scales could provide insight into comparisons in magnitude between the different departments. Two independent Y axes may be utilized when presenting data with different numeric scales in each panel.

Historical examples

Some of the earliest known examples of this type of visualization include the photographic series '' Horse In Motion'' by

Eadweard Muybridge Eadweard Muybridge (; 9 April 1830 – 8 May 1904, born Edward James Muggeridge) was an English photographer known for his pioneering work in photographic studies of motion, and early work in motion-picture projection. He adopted the first ...

, around 1886, and Francis Amasa Walker's chart of citizen's occupations in census year 1870 appearing in the ''Statistical Atlas of the United States.'' Muybridge's work not only proved for the first time that all four of a horse's hooves left the ground during gallop (see upper central plates), but it also broke new ground in terms of artistic expression and became foundational to the development of the motion picture. Muybridge went on to produce many more examples of small multiples showing animal locomotion through the medium of stop-motion photography, including boys playing leapfrog and a bison cantering. Sketched graphic examples can be found in

Francis Amasa Walker Francis Amasa Walker (July 2, 1840 – January 5, 1897) was an American economist, statistician, journalist, educator, academic administrator, and an officer in the Union Army. Walker was born into a prominent Boston family, the son of the econo ...

's charts appearing in the 1870 ''Statistical Atlas of the United States.'' Superintendent of the US Census at the time of its creation, Walker was determined to modernize the Census collection and analysis methods and used the Atlas to present the final data set using unprecedented visual forms, including many beautiful examples of small multiples. Persons With Gainful Occupations and Attending School in 1870

Persons With Gainful Occupations and Attending School in 1870

Adjacent is a chart showing the population broken down by occupation, including a count of those attending school, according to the 1870 Census. This graphic is innovative in its use of both a treemap display and a latticed layout of small multiples. Additional examples appearing in the ''Atlas'' include side-by-side geographic maps showing the changes in population over time, as well as tiled mosaic charts showing population demographic breakdowns, and diverging bar graphs showing deaths broken down by age and gender, tiled by state.

Thematic maps

Small multiples are a popular technique in

cartographic design Cartographic design or map design is the process of crafting the appearance of a map, applying the principles of design and knowledge of how maps are used to create a map that has both aesthetic appeal and practical function. It shares this dual ...

for multivariate mapping. As with the small multiple chart, each panel uses the same underlying two-dimensional space, but in this case that is a geographic space. Typically, the variables being mapped are of a similar type, such as types of agricultural products, so that the same strategy of

map symbol A map symbol or cartographic symbol is a graphical device used to visually represent a real-world feature on a map, working in the same fashion as other forms of symbols. Map symbols may include point markers, lines, regions, continuous fields, ...

can be used on each panel, enabling rapid comparison between the maps. Another common use of small multiples is to show change in spatial patterns over time, as an alternative to an animated map. Several tests of the effectiveness of each method have generally concluded that they have distinct advantages, with animation being better for seeing trends, especially movement, and small multiples being better for making comparisons between times.

References

* {{DEFAULTSORT:Small multiple Infographics