4. Analyzing Data

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

Published Online: 29 AUG 2012

DOI: 10.1002/9781118491751.ch4

Basic Statistical Tools for Improving Quality

Basic Statistical Tools for Improving Quality

How to Cite

Kang, C. W. and Kvam, P. H. (2011) Analyzing Data, in Basic Statistical Tools for Improving Quality, John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9781118491751.ch4

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



  • analyzing data;
  • confidence intervals;
  • hypothesis;
  • probability plot


Science is a systematic way of collecting data about nature and summarizing that knowledge into testable laws and theories. This chapter investigates how to quantify this knowledge through the use of confidence intervals and tests of hypotheses. It discusses how confidence intervals can help quantify uncertainty in a simple way. Like a confidence interval, a test of hypothesis helps us gauge uncertainty in an estimate. Unlike a confidence interval, this test will make a decision on whether the sample mean is large, small or sufficiently close to a target value. The probability plot provides us with a graph of the data points that have been re-scaled so that if the distribution of the data is normal, the graph will appear as a straight line.

Controlled Vocabulary Terms

confidence interval; hypothesis; probability plot