Part 1 What can you say about this lot?
Wed, 07/02/2014 - 00:00
One of the common tools of quality assurance is acceptance sampling. Acceptance sampling uses the observed properties of a sample drawn from a lot or batch to make a decision about whether to accept or reject that lot or batch. Textbooks are full of…
Tue, 06/10/2014 - 00:00
One thing burned into the brains of those who survive a statistics class is that you have to specify an alpha-level before you do anything statistical. And when it comes to statistical inference, they are correct. But just what does the alpha-level…
Mon, 05/19/2014 - 18:06
Who could ever be against having good measurements? Good measurements are like apple pie and motherhood. Since we all want good measurements, it sounds reasonable when people are told to check out the quality of their measurement system before…
Tue, 04/01/2014 - 13:59
Why bother to plot your data? A simple shortcut is available that will allow you to do your analysis without the data getting in the way. How do you accomplish this breakthrough? Read on.
This marvelous advance in analysis is known as the “data-…
Mon, 03/03/2014 - 17:46
Students typically encounter many obstacles while learning statistics. In 44 years of teaching I have discovered some distinctions that help students overcome these obstacles. This article will remove some sources of confusion concerning the…
Mon, 02/03/2014 - 16:29
Last month in “The Analysis of Experimental Data,” I presented a method for analyzing experimental data that was built on the use of the range statistic as a measure of dispersion. In this day of computers and software, why should we even consider…
Mon, 01/06/2014 - 12:26
You have spent good money obtaining your experimental results, and now the time has come to communicate those results to those who need to take action. This column will describe how to cut through the complexities of your analysis and communicate…
Mon, 12/02/2013 - 17:05
It would appear that there is still considerable confusion regarding which method to use in evaluating a measurement process. There are many voices speaking on this subject, however, most of them fail to use the guidance provided by statistical…
Thu, 10/03/2013 - 15:13
The second principle for understanding data is that some data contain signals; however, all data contain noise. Therefore, before you can detect the signals you will have to filter out the noise. This act of filtration is the essence of all data…
Mon, 09/09/2013 - 15:50
Last month’s column, “Beware the Tukey Control Chart,” generated several questions of a fundamental nature that deserve expanded answers. These questions and their answers will be considered here.
Interquartile ranges
The Tukey control chart uses…