What is a Guttman Scale? 

The Guttman scale is one of the three unidimensional measurement scales. It tests how a person responds to a specific topic and measures how positively or negatively a person reacts to a subject. 

A uni-dimensional scale means a scale that has one dimension. By using the Guttman scale in a survey, you can measure the degree of agreement or disagreement of respondents on an opinion.

Developed in the 20th century, by Louis Guttman, the Guttman scale was used to predict which test questions Louis’ students answered correctly based solely on their final score.

As a social scientist and mathematician, Guttman first applied his scale in his social science work. Now, the Guttman scale has been applied in psychology, political science, marketing, anthropology, and some other fields.

The Guttman scale can be represented by placing a numerical value on the subject. That is why getting people’s opinions on a topic might not be sufficient. You might need to specifically measure these responses.

To further understand the concept of the Guttman scale, we will examine the definition, the examples, and how the Guttman scale can be created.

Read: 7 Types of Data Measurement Scales in Research

What is the Purpose of the Guttman Scale?

The purpose of the Guttman scale is to form a one-dimensional continuation for a subject that you want to measure. What this means is that a researcher would want respondents who agree with some of the questions in a survey or questionnaire to agree with other previously asked questions.

What the Guttman scale is saying is that a researcher would like to tell the answers to a question correctly by knowing just the final score of the responder.

For example, let’s assume there is a cumulative scale of 20 questions in a survey or questionnaire. If the respondent gets a final score of 5 out of 20, then it can be interpreted as the respondent agreeing with the first five questions. Let’s assume the respondent scored 10, what it implies is that the respondent agreed with the first 10 questions. This is because the aim is to find a group of questions or items that fits into the pattern. 

In practicality, it is rare to find this accrued pattern. What researchers do in cases like this is to use the Guttman Analysis.

The purpose of the Guttman scale also known as the Scalogram scale is to establish how a set of questions or items can closely tally with the concept of cumulative scale.

Characteristics of Guttman Scale 

Here are the characteristics of the Guttman Scale.

1. It is uni-dimensional: Guttman scale statements are always in order of how difficult they get. It goes from the less difficult to the most difficult, making it uni-directional.

This means that in a Guttman Scale with 10 items if the final score of the respondent is 7, the respondent shares the same view with 7 out of the 10 items but not with the two last statements in the item list.

2. It is Deterministic: What happens here is that the results are analyzed based on the last statement on the item that the respondent agreed with. Based on how unidimensional the scale is, the responses are analyzed according to how cumulative they are on the scale.

3. It uses reproducible questions: Guttman scale uses questions that are reproducible. This means questions that cannot give the desired outcome are eliminated and the questions that can improve the outcome of the scale to the desired purpose are used. 

4. It uses the ordinal method: The questions or statements used in the Guttman scale are arranged in an ordinal way. They go from the least useful statement to the most useful statement on the list.

Read: Survey Scale: Definitions, Types + [Question Examples]

What is Guttman’s Analysis?

Guttman scaling, also known as scalogram analysis, focuses on the set of statements that the respondent agrees with on a particular subject. So Guttman analysis would like to predict responses to the statements accurately. It wants to do this by knowing only the final score of the respondent. 

Let’s consider this example.

If on a 5 items cumulative scale, the participant has a total score of three, it means the participant responded to support the first three statements. However, if the participants have a total score of 2, then the participants agreed with only the first two statements. What the scalogram analysis aims at is to analyze how a set of items relates to the cumulative scale concept.

Read: Semantic Differential Scale: Definition+ [Question Examples]

How to Interpret the Guttman Scale

Guttman’s scale can be interpreted using a graphical method called a scalogram. When the respondents and the statements( items) are put together in a table, they form a triangular pattern.

In this pattern, the respondent scores are listed in a descending manner. For instance, the scores are recorded as 5-0 or 10-0. 

The items on the other hand are listed in an ascending order that describes the level of its difficulty. It goes from the easiest item to the most difficult item. 

The interpretation is that the respondent that scores three and has an accurate response pattern responded to the three less difficult statements in an order of 1, 2, 3, and responded incorrectly to the most difficult items which are 4, and 5.

Advantages of a Guttman Scale

1. A Guttman scale can be used to respond to as many questions as possible in a short time.
2. It is more intuitive than other scales in uni-dimensional measurement which makes it appealing to researchers.
3. It shows data in a ranked way. Statements made on a scale mostly have their level of significance. Guttman scale ranks the results of those statements by the level of their importance.
4. Guttman scale reproduces statements according to how they can give the most desired response.

Read: The 4,5, and 7 Point Likert Scale + [Questionnaire Examples]

Disadvantages of a Guttman Scale

1. One downside of the Guttman scale is that it can be misinterpreted depending on who is looking at it. This is because a researcher may interpret differently e.g based on how the data is ranked while the respondent or even the judges can also interpret differently
2. The Guttman scale can be difficult to create.
3. Guttman scale may be limiting. The scale only allows limited content to be used. 

Difference Between Guttman and Likert Scale

1. The Guttman scale accepts data for what they represent, without superficially weighing the observed variables. The Likert scale, however, has one scale where it adds up the scores of the respondents because it assumes all the variables have the same weight. 
2. The Likert scale focuses on the respondents’ level of agreement or disagreement in a set of statements that follows a symmetrical scale. The Guttman scale, on the other hand, focuses on the total score of a respondent to predict a perfect response for the statements in the items.
3. A Likert scale is a psychometric scale while a Guttman scale is a cumulative scale

Explore: 13 Free Likert Scale Templates + [Questionnaire Examples]

Difference Between Guttman and Thurstone Scale

1. A researcher decides the statements used in the Thurstone scale survey by giving values to the questions. In the Guttman scale, the average level of support for a statement determines the questions to be asked. So if a statement has low support, it would be excluded from the survey questions. 
2. The standard used in deciding the results of the Thurstone scale goes from the least desired to the most desired while that of the Guttman scale is decided based on Yes or No.
3. We can apply median or mode to analyze the Thurstone scale. For the Guttman scale, the average opinions are used for analysis. 
4. The Thurstone scale’s comparable values are decided based on the understanding of the judge without considering if the mathematical calculator is wrong. Although the judge also decides the correspondence of values in the Guttman scale, unlike the Thurstone scale, it is difficult to carry out. 

Examples of the Guttman Scale

The Guttman scale measures only one specific subject. For example, this questionnaire reflects someone’s attitude to depression.

Many times, sensitive subjects are hidden in the questions in the survey to hide the actual purpose of the survey. Let’s take a look at the image below, its primary intent is to find out about the possibility of being addicted to gaming. See how the questions are laid out.

Another example, look at the statements listed out about a person’s relationship with a snake.

1. I will look at a snake in the zoo from a distance
2. I will go close to a snake
3. I will touch a snake
4. I will own a snake as a pet
5. I will keep a snake on my bed

Note how the statements are listed in order of difficulty. The level of difficulty kept increasing. Guttman scale starts the statement in an item in ascending order. It goes from the least difficult to the most difficult.

How to Create a Guttman Scale Questionnaire with Formplus

What Formplus does is allow you to gather diverse information from your survey respondents with its online forms. It has over 1000 dynamic form templates that you can choose from depending on your need.

Creating a survey on the Guttman scale with Formplus is pretty seamless.

Here is a detailed guide on how you can use Formplus to create the Guttman scale in your survey form.

1. Sign in to Formplus: If you don’t have an account, you can signup for free.

2. Once you’re signed in to Formplus, click on ‘create new form’.

3. From there, you will be directed to the form builder, you can easily build your Guttman scale into your survey form using the drag-and-drop feature. Under “Inputs” click on the “Ratings” option. 

The Rating section will show a drop-down menu of the rating scale options available in the form builder. 

4. Click on the “scale” rating option, then click the edit button to modify the scale to suit your survey questions. You can also set your form to read-only and you can make it hidden.

5. Once you’ve done all the necessary modifications, click on the “Save” button. You can then proceed to preview your survey form. 

To set the tone for your Guttman scale survey, focus on these three outlines. They’ll guide you in building your form.

1. Define the topic: the first thing you should do is define your research subject. You need to carefully develop research questions or statements that go in line with the particular opinion or topic you want to conduct a survey on.

2. Generate related questions to your topic: The statements can be close-ended questions that require just “yes/no” or “agree/disagree” response options.

Another thing to ensure is that all the statements are closely related in the series of questions. They all must tend towards the same subject matter but the level to which they relate to the subject can differ. Note that to have a more accurate result, your survey questions or statements must increase in numbers. This is because the higher the questions, the better the results. 

3. Score the questions: To create a Guttman scale survey, you must input a score or grade to each one of the questions or statements. 

Follow these steps one after the other and you will create your own unique and effective survey form.

Best Formplus Features to Use in a Guttman Scale

As earlier discussed, you can use the drag and drop feature to use all your preferred features on your form.

Another feature to use is the Basic Select. This Basic Select template is best to use for close-ended questions such as questions developed for the Gutman scale survey. It allows the respondent to choose only one answer. To maximize this feature, you will include the action you want which can be Yes or No or Agree and Disagree. 

Besides these two features, Formplus can also provide insight into your survey. If you want to interpret your survey results, and analyze them, Formplus lets you do that too.

Conclusion

We have discussed how the Guttman scale can be used in a survey and equally discussed how you can interpret the results. If you’re interested in conducting a survey on the opinions of people about a particular topic, you should definitely use a Guttman scale.