It’s Day Three of Scale Week and if survey rating scales were ice cream flavors, the Likert scale would be pure vanilla. It’s commonplace and unglamorous. Some might even call it old-fashioned. But it works and is useful in a wide variety of situations.

Scale #3 – Wednesday

In fact, the Likert scale is so widely used that some people use the name Likert interchangeably with any type of rating scale. A true Likert or “Likert-type” scale presents the respondent with a series of statements and asks them to indicate their level of agreement with those statements by using a scale with an odd number of points. Five-point scales are the most popular variety, but seven-point scales are also commonly used. A typical Likert scale looks like this:

It is also common to use numbers along with, or in place of the code labels like this:

Another technique that works well when using a larger scale or when administering the survey over the phone, is to present the scale numerically with only the extremes and the midpoint labeled.

There is some debate among researchers as to whether or not the points of a scale should be labeled. My own personal opinion is that the vast majority of people intuitively understand a numbered rating system. If you ask them to rate their agreement on a scale from one to five and establish that five means “strong agreement,” they’ll get it. After that, the point labels simply become window dressing. And, in some cases, they can actually confuse the issue, as they raise the question about the fine distinctions between adjectives describing degree. Consider this nine-point scale for example:

Is “mildly” really less than “moderately?” And even if it is, is the semantic difference between “moderately agree” and “mildly agree” roughly equal to the difference between “moderately agree” and “agree?” I honestly don’t know. And frankly it’s not something I want to think too hard about. I certainly don’t want a respondent wondering about it, to the point of distraction, when they are in the middle of a survey. That’s why I believe the example below is much cleaner, more intuitive, and more user-friendly.

The advantages of the Likert scale are many. It’s a quick and easy way to measure the degree to which respondents feel a certain way. Because it is so commonly used, it doesn’t normally require a great deal of explanation to complete or create confusion on the part of the respondent. From the standpoint of analysis, the findings are easy to numerically tabulate, graph, and report in such a way that even the most number-averse client can understand at a glance.

But it’s always possible to have too much of a good thing. Too many Likert scales in a survey instrument can lead to respondent fatigue and “straight-lining” (the practice of giving all attributes the same rating down the line without thinking about it in order to complete the survey faster). It is often argued that a person’s response to earlier rating questions can sometimes bias their responses later on in the survey. Another pitfall, which is often seen in DIY research administered with Survey Monkey and similar applications, is the tendency of novice survey writers to slip simple yes or no questions into a series of rating questions, as with the third item in the example below:

So there you have it, the humble yet versatile Likert scale. It might not be the sexiest rating scale we write about during Scale Week, but it’s a true workhorse. It should be an item in every survey writer’s toolbox. As long as you don’t overdo it or use it for the wrong kind of question, the Likert scale will serve you well.

• Click Here to view the Day 1 post on Constant Sum Scaling.
• Click Here to view the Day 2 post on Semantic Differential Scaling.
• Click Here to view the Day 4 post on Scaling Mistakes | What Not to Do.
• Click Here to view the Day 5 post on 6 Tips for Using Rating Scales.