Guttman Scale definition:
A Guttman scale (also known as cumulative scaling or scalogram analysis) is an ordinal scale type where statements are arranged in a hierarchical order so that someone who agrees with one item will also agree with lower-order, easier, less extreme items. These statements should reflect an increasing intensity of attitude and form a continuum that is accepted by the respondents. The point at which the respondent disagrees with a statement reflects the respondent’s scale position.
A Guttman scale presents a number of items to which the person is requested to agree or not agree. This is typically done in a 'Yes/No' dichotomous format. It is also possible to use a Likert scale, although this is less commonly used.
Guttman scales are very commonly used in political science, anthropology, public opinion, research, and psychology.
Guttman scale advantages:
- It can be used to answer many questions in a short amount of space and/or time.
- It is intuitively appealing to most people.
- It provides ranked data.
- More one-dimensional than Likert scaling
Guttman scale disadvantages:
- The rank order of the statements may not be interpreted in the same way by the researcher, the subject or by independent judges.
- Difficult to construct
- Scalogram analysis may be too restrictive, only a narrow universe of content can be used
- Cornell technique questionable
- Results no better than summated Likert scales
Guttman scale examples
The ideal Guttman scale is such that if the respondent disagrees, for example, with statement 4 (having agreed with statements 1 to 3) then the respondent will disagree with statement 5 and higher as these represent more extreme expressions of the attitude being investigated.
For example, a series of items on attitude could be
- "I am willing to be near a cat"
- "I am willing to have a cat"
- "I love to have a cat"
- "I am willing to touch a cat"
Or a series of items on difficulty:
- counting from 1 to 50
- solving addition problems
- solving subtraction problems
- solving multiplication problems
- solving division problems