• OGC Global

A Guide to Monadic Testing


Who hasn’t been confused by too many choices? When several options are presented, people can get confused or their choice can be biased by the order the options are displayed.

As a market researcher, how can you ask your customers to rank different concepts for you to know which one to launch? How can you be sure that your data is of good quality and your respondents haven’t been biased or confused by all the concepts that you have presented to them? In order to keep your customers engaged once they start filling in a survey, you should only ask questions you need to know.

One of the biggest factors in responder engagement is duration or length of survey. By proposing a monadic survey, you considerably reduce the length of your survey and thus, encourage engagement. But what is a monadic survey exactly, and how can I be sure it is the right survey type for my market research? This article will answer and discuss those questions in depth.

Definition: The term “monadic” comes from Greek μοναδικός meaning “single”. In a monadic survey each element (stimulus, product, concept, etc.) is displayed and evaluated separately.

The approach in a monadic survey is to divide the target population into subgroups (as many subgroups as the number of stimuli we have) and show only one stimulus to each subgroup.

Since all participants belong to the same group, it is fair to compare the responses of all subgroups to determine which stimulus was the best ranked and is selected as “the winner”. In opposition to the monadic survey, there is the comparison testing, where several stimuli are tested side-by-side.

How to Apply a Monadic Survey?

Let’s take the example of a sun screen company that has 4 different packaging options, and would like to rank them in order to commercialize the most appreciated one. To do so, they will use a monadic survey.

They will split their respondents into 4 different groups (because there are 4 different products). Each group will evaluate each concept. All the subgroups have to be equivalent so the results can be compared. To ensure it, a quota system needs to be applied.

Once the 4 groups give their opinion about the product they were shown, the results of the 4 sunscreens are compared in order to decide which one is the most appreciated by the customers.

Why a Monadic Test?

Customers can easily become overwhelmed with surveys that include extensive lists of concepts or product features. Especially when it comes to complex stimuli like videos, long texts, or stimuli that have very little differences.

The attention can drop and concepts shown at the end might not be noted with the same level of attention. Concepts can also be mixed up by the respondent and the data don’t bring insight then. By showing only one product at a time, the survey eliminates all possible confusion a respondent might have and allows focusing his attention only on one product.

Another advantage to show only one stimulus to each respondent is that the questionnaire can be shortened considerably. If you would like to ask 10 questions about each stimulus, in a comparison survey, the length of the survey would be 10 times the number of stimulus you would like to compare.

The more stimuli you have, the longer it becomes. With a monadic survey, each respondent will receive only 10 questions! Since the surveys are shorter, questions can be asked more in detail about each concept. It allows you to have a more in-depth understanding of how customers perceive each of the concepts you present to them.

However, before implementing a monadic testing survey, you should be informed of the disadvantages. The more stimuli you want to evaluate, the more respondents you will need. If 100 people need to fill the survey to fill your quota, then you will need 100 people for each stimulus.

The number of respondents needed can grow quickly depending on the number of concepts you have. On the contrary, if you show all the concepts at the same time to all your respondents, only 100 people are required.

Here is a list of advantages and disadvantages in summary:


  • No confusion by mixing several concepts

  • Data of better quality

  • Reduces survey fatigue

  • The result of concepts are not biased by the order of presenting the concepts

  • Survey length is shortened

  • More Key Drivers can be surveyed


  • More respondents are required

Can You Use a Monadic Survey Design?

In order to apply the monadic testing to your survey, you need to be sure that all the points mentioned above will improve your data and won’t affect your results. You need to ensure that:

  • There are only a few concepts you want to test. As said above, the more concepts we have, the more respondents we need.

  • Collecting a large sample is possible. We will need a bigger sample size than with a comparison testing.

  • Each concept is time consuming to interpret. If every concept is easy to understand, clearly distinct from the others, and can be quickly acquired, respondents then will not be confused or experience survey fatigue if a comparison test is applied.

Types of Monadic Tests

There are different types of monadic surveys, the most popular being the A/B testing:

  • Split-cell monadic

  • A/B testing

  • Sequential monadic

  • Discrete choice as an alternative technique


The monadic testings are advantageous in order to not confuse the respondent, reduce the survey length, reduce the survey drop, and have more accurate results. However, the monadic testing should be chosen with full knowledge of the pros and cons as it is more pricey than other surveys due to the large sample size required.

Johanna Benhamou, Analyst

#cx #datavisualization #mondaictesting #testing #customerexperience #business #NPS #ogcglobal #survey #surveydesign

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