Did you see the broken light?

datalsurveydesign.gif“Three decades ago, a group of students were shown a short movie in which two cars were in an accident. Then the students were divided into two groups where the first group was asked "Did you see the broken light?" and the second was asked "Did you see a broken light?" Switching one single word, the or a, in the otherwise identical question changed responses by an astonishing 31 percent.

A body of literature has shown that there are many ways to influence respondents, too often too subtle to be recognized. You can probably guess that using the word "financial incentives" or "subsidies" will elicit different results. But would you think that the order in which different alternatives are presented to the respondent might influence his or her response? Probably not, but in reality it does.

Irrespective of how the question is worded, survey methods that could influence the data collected, such as using or not a public official as interviewer or reading the questions to the respondents instead of showing them written questions are known as survey fixed effects. Not taking such effects into account can bias the results, says Iarossi.”

- A review of the book, The Power of Survey Design: A User's Guide for Managing Surveys, Interpreting Results, and Influencing Respondents by by Giuseppe Iarossi

The book is a must read for anyone interested in anything to do with surveys.

Some other book reviews in the latest F&D.


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This page contains a single entry by Paul published on May 30, 2006 4:55 PM.

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