2. Graphical Display of Data

  1. Chang W. Kang1 and
  2. Paul H. Kvam2

Published Online: 29 AUG 2012

DOI: 10.1002/9781118491751.ch2

Basic Statistical Tools for Improving Quality

Basic Statistical Tools for Improving Quality

How to Cite

Kang, C. W. and Kvam, P. H. (2011) Graphical Display of Data, in Basic Statistical Tools for Improving Quality, John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9781118491751.ch2

Author Information

  1. 1

    Department of Industrial and Management Engineering, Hanyang University, South Korea

  2. 2

    School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, GA

Publication History

  1. Published Online: 29 AUG 2012
  2. Published Print: 8 APR 2011

ISBN Information

Print ISBN: 9780470889497

Online ISBN: 9781118491751



  • bar chart;
  • eZ SPC;
  • graphical display of data;
  • histogram;
  • pareto chart;
  • pie chart;
  • qualitative data;
  • quantitative data


This chapter introduces the analysis of SPC data through computer graphics with the help of the statistical software called eZ SPC. This is a simple program in the form of a spread-sheet with commands selected from a drop-down menu, very much like Microsoft Excel. The kind of data we run across in SPC problems can be categorized as qualitative and quantitative. To a statistician, qualitative data analysis is a less informative way to describe a set of data. Similar in function to the bar chart, the pie chart is a circular graph to show frequencies, but now the plot features the relative frequencies of the observations with regard to the other categories. The Pareto chart is a relatively new tool in SPC, but it is an old standby in economics. Histogram is a graphical display of frequency data with bars. With a histogram we can check the distribution of data.

Controlled Vocabulary Terms

bar chart; graphical model; histogram; pareto chart; pie chart