A Likert Scale survey is a psychometric scale commonly used in research studies to capture accurate opinions. It is the most widely used scale in survey research, such that the term is often used interchangeably with rating scale even though the two are not synonymous. 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.
Now, what exactly are the differences between Unipolar Likert scales and Bipolar Likert scales? Let’s look at each scale individually:
Unipolar Likert scale
Unipolar scales are more contoured, allowing users to instead focus on a single item’s absence or presence. The scale measures the ordinal data, but most of the time, unipolar scales generate more accurate answers. An example of a unipolar satisfaction scale is: not at all satisfied, slightly satisfied, moderately satisfied, very satisfied, and completely satisfied. A unipolar Likert scale question type indicates a respondent to think of the presence or absence of a quality or trait. For example, a common unipolar scale includes the following choices: not at all satisfied, slightly satisfied, moderately satisfied, very satisfied, and completely satisfied. It is arranged on a 5 point scale. A to E. Also, Unipolar question types lend themselves where there is a maximum amount of the attitude or none. For instance, let’s say, how helpful was the apple pie recipe? Very helpful, somewhat or not at all. We can safely assume there is something in between–like “sort of” helpful.
Bipolar Likert Scale
A bipolar scale indicates a respondent to balance two different qualities, defining the relative proportion of those qualities. Where a unipolar scale has one “pole,” a bipolar scale has two opposites. For example, a common bipolar scale includes the following choices: completely dissatisfied, mostly dissatisfied, somewhat dissatisfied, neither satisfied nor dissatisfied, somewhat satisfied, mostly satisfied, and completely satisfied. That is a scale with 0 in the middle (-3, -2, -1, 0, 1, 2, 3).
Why are Likert scales essential in research?
Instead of giving the respondent a dichotomous question with the only options being “yes” or “no,” Likert scales feature degrees of feeling (usually 4, 5, or 7) so that market researchers can attain a more accurate response. Further, you can quantify and statistically analyze qualitative attributes such as feelings and emotions. Here is a guide to when, where, and how to use Likert scales.