Survey Scales

Survey scales measure variables that researchers infer from other directly measured variables.

Likert Scale

One of these types of scales, called the Likert scale, is the most popular type of scale.  Likert scale questions require survey respondents to select their level of agreement to a statement.  For example, response categories may be responses such as ‘strongly agree,’ ‘agree,’ ‘don’t know,’ or ‘disagree.’

Guttman Scale

Another scale is called the Guttman scale.  In this scale, the items are made in a single dimensional series.  This is so that the response given by the respondent for a certain item predicts the responses for all of the previous items in that series.  For example, a proximity scale assumes that a positive response to a complex question predicts a positive response to a simpler or less sensitive one. This is based on the idea that mood or mindset influences responses.

Mokken Scale

There is another type of scale, called a Mokken scale.  Since Guttman scales are quite rigid and determinable, Mokken scales are available to do what Guttman scales cannot.  The major difference between these two types of scales is that the Guttman scales are deterministic, while the Mokken scales are probabilistic.  In the previous example, according to the assumption of Mokken scales, if the respondent responds to a particular question in a positive manner, then there will be a significantly greater probability that the respondent will respond to a less complex question in a positive way as well.