Bar Chart
effective way to compare the values of different items in a specific category - e.g., distribution of student credit hours between majors and non-majors in a course or unit. See: http://en.wikipedia.org/wiki/Bar_Chart
Line Chart
typically compares changes and correlations of two or more numerical aspects of a single object - often over a time period. For example, a comparison between GOF and RCR levels over a six year period. See: http://en.wikipedia.org/wiki/Line_chart
Pie Chart
provide a simplistic visual when trying to see at first glance how something has been divided up, such as unit spending, survey feedback, or faculty ranks, or grants percent for each department. Best used for describing the relationship of one part to the whole. A relative value chart is a rectangular version of the pie chart. See: http://en.wikipedia.org/wiki/Pie_chart