Pareto and Bar Charts

Date: 03/12/97 at 07:38:35
From: mike king
Subject: Pareto and Bar charts

Hello,

I am asking for my nephew.  His book is somewhat shallow on this 
subject.  My question is, what are three distinguishing differences 
between Pareto Charts and Bar Charts?

As I look at them from his book, it seems that they are very similar. 
I can't seem to find much of a difference other than a percentage line 
up the right side of a pareto chart.

Thanks.

Mike

Date: 03/12/97 at 14:49:21
From: Doctor Mike
Subject: Re: Pareto and Bar charts

Hello,   
  
I used AltaVista to do an Internet search for information.  A Pareto 
chart is a special kind of bar chart used for a special purpose. The 
following explanation and a good color example of one can be found at:

  http://www.sas.com/rnd/app/qc/qcparish.html   
  
The Pareto chart, used to determine priorities for quality improvement 
activities, is a bar chart that displays the relative frequency of 
problems in a process or operation. Each bar represents the relative 
frequency of a problem, and the bars are arranged in decreasing order 
from left to right. Sometimes a curve is superimposed to indicate the 
cumulative percent of problem frequencies. The chart is named after 
Vilfredo Pareto (1848-1923), an Italian economist. 

Pareto charts provide a tool for visualizing the Pareto principle, 
which states that a small subset of problems (the "vital few") 
affecting a common outcome tend to occur much more frequently than the 
remainder (the "useful many"). A Pareto chart can be used to decide 
which subset of problems should be solved first, or which problems 
deserve the most attention. Pareto charts are often constructed to 
provide a before-and-after comparison of the effect of control or 
quality improvement measures. 

Another nice example is at

  http://www.theriver.com/qa-inc/paretoch.html   

-Doctor Mike,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/