https://achilleaskostoulas.com/2013/09/09/four-things-you-probably-didnt-know-about-likert-scales/
Likert scales are among the most frequently used instruments in questionnaire surveys. A Likert scale consists of statements and pre-defined responses that measure the intensity of the respondents’ feelings towards the preceding statement. Here’s an example of such as a statement, or ‘item’:
Figure 1. Example of a Likert item (Purists might argue that the response options must be displayed horizontally. They are technically correct, but I can’t be bothered to change the figure, so they can argue on…)
Likert scales are easy for respondents to understand, and easy for researchers to interpret, which is why they are used very frequently in student projects and more formal research. However, despite their popularity (or maybe because of it), they are often used in loose ways that are not always optimal.
Here are four tips to help you avoid common pitfalls. In this post you will learn:
Likert scales were created by Rensis Likert, a sociologist at the University of Michigan. The proper pronunciation of his name is “Lick – uhrt”. The pronunciation “like – uhrt”, though common, is incorrect.
A Likert item consists of a prompt and a set of responses. Most frequently, there are five responses for each item, often ranging from Strongly agree to Strongly disagree. Seven-item scales are also quite common. When using an odd number of responses, the mid-range is a ‘neutral’ option, such as “no opinion”, “neither agree nor disagree”, “not sure” or some phrase to that effect.
Such a practice can be problematic for at least two reasons: Firstly, many respondents tend to avoid voicing extreme opinions or taking a stand on controversial topics. This means that respondents are likely to select a ‘safe’ choice at the centre of the scale if one is available, rather than reveal their ‘true’ opinion – a phenomenon called the central tendency bias. This is especially the case when respondents are conscious of power imbalances (e.g., students responding to a questionnaire designed by their professors or teachers engaging with university-based research).
A second potential problem with middle options is that they can be hard to interpret. While we might assume that it means something along the lines of ‘I have no strong views either way’, this may not be true of all respondents. For some respondents, for example, the ‘neutral option’ could mean that ‘I don’t care either way’; for others it may mean that ‘I have no knowledge of this’.
Figure 2. A ‘forced-choice’ Likert item