This is the program for the 2010 Joint Statistical Meetings in Vancouver, British Columbia.

Abstract Details

Activity Number: 187
Type: Contributed
Date/Time: Monday, August 2, 2010 : 10:30 AM to 12:20 PM
Sponsor: ENAR
Abstract - #308979
Title: Pitfalls of Simplistic Normalization in Basic Science Experiments
Author(s): Tatsuki Koyama*+ and Zhiguo Zhao and Jeffrey Blume
Companies: Vanderbilt University School of Medicine and Vanderbilt University School of Medicine and Vanderbilt University School of Medicine
Address: 571 Preston Research Building, Nashville, TN, 37232-6848,
Keywords: fold change ; normalization ; type I error

Basic science experiments often use a separate control group for each treatment group. Typically, the treatment group outcomes are scaled by the average of the corresponding control group outcomes. Despite its overwhelming popularity, this "fold change" method has serious statistical problems resulting in reduced validity and efficiency. When the implicit variability of the control group outcomes is ignored, a large type I error inflation can result. Likewise, this scaling induces correlation and can substantially inflate the type I error when this correlation is ignored (as it often is). We present simulations showing that this inflation results in type I error rates as high as 50% in everyday settings. We propose some computational and analytical approaches for dealing with this problem, and we present some practical recommendations for experimental designs with small sample sizes.

The address information is for the authors that have a + after their name.
Authors who are presenting talks have a * after their name.

Back to the full JSM 2010 program

2010 JSM Online Program Home

For information, contact or phone (888) 231-3473.

If you have questions about the Continuing Education program, please contact the Education Department.