Case Studies and White Papers

Analyzing Two-Level Factorials Having Missing Data

Published: January 1993
Authors: Kinley Larntz, Patrick Whitcomb

This presentation details and demonstrates a procedure that, despite missing data, allows the use of user-friendly, normal-probability plots for two-level-factorial effect selection.

Publication: Fall Technical Conference, St. Louis

DOE It Yourself

Published: January 1992
Author: Mark Anderson

Fun science projects.

Publication: Stat-Ease, Inc.

A Simple Comparative Experiment with Paper Clips

Published: January 1992
Author: Mark Anderson

Details and demonstrates a fun experiment to do at home or in class to build understanding of variation and how it can be handled with simple comparative designs. For teaching purposes it works best if each student breaks two brands of clips, thus providing data for a paired t-test, which blocks out variability due to the tester.

An updated version of paper-clip experiment is provided in the June 2009 Stat-Teaser posted at

Publication: Stat-Ease, Inc.

Published: January 1992
Authors: Patrick Whitcomb, Kinley Larntz

A look at augmenting the usual probability plot effects with points representing pure error.

Publication: Conference

Experiments Uncover Source of Valve Failures

Published: June 1988
Authors: Nancy Chase, Dan Selness

Company engineers at Fluoroware Ind. chose to use Design-Expert software to troubleshoot customer complaints that their plastic components were failing prematurely. In the past, doing this sort of test could be very complicated; however, using DOE to test multiple factors at once significantly simplified the process.

Publication: Quality Magazine

How to Document Process Monitoring and Control Systems

Published: September 1981

Maximize plant capability and efficiency by developing specifications for all aspects of a process.

Publication: Chemical Engineering