Data Presentation

There are three basic components to most charts:

• Labeling that defines the data: the title, axis titles and labels, legends defining separate data series, and notes (often, to indicate the data source),

• Scales define what's on each axis and the range of the Y (and sometimes the X) axes

• Graphical elements that represent the data: the bars in bar charts, the lines in times series plot, the points in scatterplots, or the slices of a pie chart.

Graphs and Charts

• Pie Charts used to represent the distribution of the categorical components of a single variable. 

• Bar Charts display the relationship between one or more categorical variables with one or more quantitative variables represented by the length of the bars.

• Time series line charts: effiicient way to display large amounts of data.  The typical time series line chart is a scatterplot chart with time represented on the X-axis and a best fit line connecting the data points.

• Scatterplots: most efficient for the graphical display of data.  A simple scatterplot reveals the relationship between two variables.

• Boxplots: used to compare distribution of the same variable for two or more groups or two or more time points

Types of Charts

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f(x) = 1150.30600859507 ln(x) − 1193.46627204969

f(x) = 12.56 x² − 1.40338079256337E-13 x + 5.000341514867E-13R² = 1

Surface Area of Sphere vs Radius

r (cm)

SA

(c

m2

)

T. Hayes et al., (2003) Atrazine-Induced Hermaphroditism at 0.1 ppb in American Leopard Frogs

Atrazine Levels at Sample Sites along the Mississippi River

DATA PRESENTATION

- Each pair of students gets a copy of one the following graphs.

- With your partner, discuss your graph, figure it out and practice presenting it to the class in a clear and complete way.

- Each pair of students will present their graph

- Audience “critiques” based on whether they completely understood the graph based on the presentation

Janet N. Abramovitz and Ashley T. Mattoon, Paper Cuts: Recovering the Paper Landscape, Worldwatch Paper 149 (Washington, DC: Worldwatch Institute, December 1999)

United Nations Food and Agriculture Organization (FAO), FAOSTAT Statistical Database, faostat.fao.org, updated 15 September 2006

Frank Keppler and Thomas Rockmann, Methane, Plants, and Climate Change, Scientific American, 2007, p. 52-57

D. Renault and W. Wallender, Nutritional Water Productivity and Diets, Agricultural Water

Management, vol. 45, 2000, p. 275-96

FAO, FAOSTAT Statistical Database, at apps.fao.org, updated 20 December 2004

C. DeWit et al., Levels and Trends of Brominated Flame Retardants in the Arctic, Chemosphere 64, 2006, 209-233

Brominated Flame Retardants at Sample Sites in the Arctic

(2003)

A. Murata et al., Electricity Demand in the Chinese Urban Household Sector, Applied Energy (2008), vol. 85, p. 1113-1125