Posted by: tonyteaching | January 6, 2010

Likert Scale: 5 or 7 points?

by Glen O’Neil at http://www.isixsigma.com/offsite.asp?A=Fr&Url=http://intelligentmeasurement.wordpress.com/2007/11/20/likert-scale-surveys-best-practices/ (November 20, 2007)

Actually most studies are not conclusive on the difference between 5 and 7 points on a scale. In other words, both 5 & 7 point would provide you with accurate and reliable responses.

In the article listed below, they conclude that as you add more points, a scale becomes more reliable – but only up to a certain point (higher than 11 is too much for most people). Consequently, they argue that 7 is slightly more reliable than 5.

I would recommend that you use a 7 point scale, particularly if you have other comparative variables that you are going to measure on a 7 point scale – it makes it much easier to compare and avoids having to re-calculate your results.

The article I mentioned:

Alwin, D & Krosnick, J, “The reliability of survey attitude measurement: The influence of questions and respondent attributes”, Sociological Methods Research, 1991; 20; 139
http://smr.sagepub.com/cgi/content/abstract/20/1/139


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