Population Profile

http://www.ifad.org/operations/regional/pf/aids_1.htm

A population profile shows the amount of people in an area as related to their age. A third variable can be brought in as well, such as AIDS as shown in the above example.

Scatterplot



http://www.netmba.com/statistics/plot/scatter/

In research, a scatter plot is used when there is a variable that is being manipulated by the experimenter. Normally the independent variable is plotted on the horizontal axis and the dependent variable is plotted on the vertical axis as shown in the example above.

Index Value Plot

http://waterwatch.usgs.gov/new/index.php?r=11&m=pa07d_dry&w=plot

An index value plot is a visual map that shows an index of measurements. The above is showing the percentage of stations that are above and below the expected percentage over a decade.

Lorenz Curve

http://www.unc.edu/depts/econ/byrns_web/Economicae/Figures/Lorenz.htm

The above is an explanative example of a Lorenz Curve.  This type of graph is used to express inequality among two related variables; in the above example: income and population.  Lorenz Curves are also useful in determining the GINI coefficient relating to inequality.

Bilateral Graph

http://www.econbrowser.com/archives/2010/09/the_yuans_cours_1.html

A bilateral graph, like the one above shows data sets that hold both positive and negative values.  Notice how the "Real bilateral rate" value dips below 0, requiring the use of a bilateral graph.



Nominal Area Choropleth Map

https://courseware.e-education.psu.edu/courses/geog482/policies.shtml

A nominal choropleth map is unique from other choropleths in that it presents data under labels or categories as opposed to specific numerical values.  It is a simpler map that usually deals with absolute conclusions, as in the case of this map showing, simply which minority group has the highest percent of the population in any given state.  Notice the variables are presented as the categories of race, not the percentages specifically.

Unstandardized Choropleth Map

http://flowingdata.com/2009/11/12/how-to-make-a-us-county-thematic-map-using-free-tools/

A Unstandardized Choropleth Map shows a large region shaded in different colors, such as the one above of the United States. They are used to take raw numbers from data instead of standardizing the values, hence the word "unstandardized."