A Likert scale is a psychometric scale commonly used in questionnaires, and is the most widely used scale in survey research. When responding to a Likert questionnaire item, respondents specify their level of agreement to a statement. The scale is named after its inventor, psychologist Rensis Likert.
An important distinction must be made between a Likert scale
and a Likert item
. The Likert scale
is the sum of responses on several Likert items
. Because Likert items
are often accompanied by a visual analog scale (e.g., a horizontal line, on which a subject indicates their response by making a circle or a check mark), the items are sometimes called scales themselves. This is the source of much confusion; it is better, therefore, to reserve the term Likert scale
to apply to the summated scale, and Likert item
to refer to an individual item.
A Likert item
is simply a statement that the respondent is asked to evaluate according to any kind of subjective or objective criteria; generally the level of agreement or disagreement is measured. Often five ordered response levels are used, although many psychometricians advocate using seven or nine levels; a recent empirical study found that a 5- or 7-point scale may produce slightly higher mean scores relative to the highest possible attainable score, compared to those produced from a 10-point scale, and this difference was statistically significant.
The format of a typical five-level Likert item is
1. Strongly disagree
3. Neither agree nor disagree
5. Strongly agree
Likert scaling is a bipolar scaling method, measuring either positive or negative response to a statement.
Wikipedia, the free encyclopedia. Likert scale. Internet. Accessed on December 16, 2009.