Issues in Data Collection

Share Button

There are a number of issues that we must consider when collecting and using data for analysis purposes.  One of those issues is the Hawthorne Effect, also referred to as the observer effect.   This is a phenomenon where individuals change their behavior because they know they are being observed or watched.    The term was coined in 1950 by Henry Landsberger based on his analysis of experiments that were previously conducted at the Hawthorne Works, a Western Electric factory near Chicago.

The study was conducted to see whether or not increased levels of light had any impact on worker productivity.  Worker productivity improved when the study began and slumped when it ended, indicating that the workers were motivated based on the interest that was being shown in them and not on the physical changes that were made to the workplace.  While interpretations and views of the original studies vary, we must be aware when collecting data that worker behavior may change simply because of the attention paid to their work and not based on any changes that are made to their work process.

Another issue that often comes up is whether to rely on existing data or to collect new data.  The best decision is not always obvious.  We must assess what data already exists, the quality of the data, and whether the data are in a useable format.

The use of existing data offers the advantages of lower cost and immediate availability.  It is also possible that new knowledge may be derived from the study of existing data.  However, we must recognize that existing data may not have been collected from the correct population or in the proper manner.  The data may be of poor quality, with missing or incorrect values.  The data may be confounded by factors that were not accounted for during the collection process.

Collecting new data offers the advantage of greater control over measures, procedures and the people who collect the data.  These factors usually result in greater validity and reliability of the data.  The obvious disadvantage is the additional time and cost that is involved in collecting the new data.

Your comments or questions about this article are welcome, as are suggestions for future articles.  Feel free to contact me by email at

About the author:  Mr. Roger C. Ellis is an industrial engineer by training and profession.  He is a Six Sigma Master Black Belt with over 45 years of business experience in a wide range of fields.  Mr. Ellis develops and instructs Six Sigma professional certification courses for Key Performance LLC.   For a more detailed biography, please refer to

Share Button

On December 8th, 2014, posted in: Six Sigma by Tags: ,

Leave a Reply