Likert scale is a psychometric scale where questions based on this scale are normally used in a survey. It is one of the most widely used question types in a survey. In a likert scale survey respondents simply don't choose between "yes/no", there are specific choices based on "agreeing" or "disagreeing" on a certain question in the survey.
Likert scale survey questions are essential in measuring a respondent's opinion or attitude towards a given subject and is an integral part of market research. Likert scale is typically a five, seven, or nine-point agreement scale used to measure respondents' agreement with a variety of statements. Organizational psychologist Rensis Likert developed the Likert Scale in order to assess the level of agreement or disagreement of a symmetric agree-disagree scale. In general, a series of statements each designed to view a construct from a slightly different perspective is leveraged. The power of this technique is that it works across disciplines—it is just as applicable to a social science construct as it is a marketing one.
Likert scale usually has five, seven or nine points, with five and seven points used most frequently. For example, typical multiple-choice options include strongly agree, agree, no opinion, disagree and strongly disagree as the likert item. In a likert survey, adding "Somewhat" to both sides creates the sixth and seventh points. The scales are anchored by strongly agree and strongly disagree. There is some research that indicates having the agree side shown first could inflate the scores. This likert scale data can be tested by alternating the anchor points within a survey wave and comparing scores in the data analysis stage.
Likert scale is designed to measure attitudes that are multi-item. Basic research tells us that multiple-item measures of a construct are inherently more stable and subject to less random variability than single-item measures. How many items are enough? If you are creating a new scale then you should create as many items as possible and let subsequent analysis narrow the field of contenders. This can be done through brainstorming sessions, focus groups or a review of existing literature. Look at the Likert scale samples below for an even better understanding.
Unipolar scales are more contoured, allowing users to instead focus on the absence or presence of a single item. The scale measures the ordinal data, but most of the times 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 quality. 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 of it. For instance, let's say, how helpful was the apple pie recipe? Very helpful, somewhat or not at all. From there, we can safely assume there is something in between–like "sort of" helpful.
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 polar 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).
See an example of bipolar likert scale questions in our Motivation and buying experience survey template
Let us consider the following statements :
The first two statements measure the customer's perceptions about
the business. Traditionally the Net Promoter Score question is used to conduct a customer satisfaction survey. Qualitative research such as focus groups or in-depth interviews can be useful
in helping to generate a list of statements. The last three statements were centered on the
individual and might be part of an opinion leader or early adopter scale. Just as easily you
can create a scale with items touching upon political or social topics, religion, or other
important issues of the day.