Page:Online Statistics Education.pdf/65



A. Qualitative Variables

B. Quantitative Variables C. Exercises
 * 1) Stem and Leaf Displays
 * 2) Histograms
 * 3) Frequency Polygons
 * 4) Box Plots
 * 5) Bar Charts
 * 6) Line Graphs
 * 7) Dot Plots

Graphing data is the first and often most important step in data analysis. In this day of computers, researchers all too often see only the results of complex computer analyses without ever taking a close look at the data themselves. This is all the more unfortunate because computers can create many types of graphs quickly and easily.

This chapter covers some classic types of graphs such bar charts that were invented by William Playfair in the 18th century as well as graphs such as box plots invented by John Tukey in the 20th century. 65