The four types of validity

In quantitative research, you have to consider the reliability and validity of your methods and measurements.

Validity tells you how accurately a method measures something. If a method measures what it claims to measure, and the results closely correspond to real-world values, then it can be considered valid. There are four main types of validity:

  • Construct validity: Does the test measure the concept that it’s intended to measure?
  • Content validity: Is the test fully representative of what it aims to measure?
  • Face validity: Does the content of the test appear to be suitable to its aims?
  • Criterion validity: Do the results correspond to a different test of the same thing?

Note that this article deals with types of test validity, which determine the accuracy of the actual components of a measure. If you are doing experimental research, you also need to consider internal and external validity, which deal with the experimental design and the generalizability of results.

Construct validity

Construct validity evaluates whether a measurement tool really represents the thing we are interested in measuring. It’s central to establishing the overall validity of a method.

What is a construct?

A construct refers to a concept or characteristic that can’t be directly observed, but can be measured by observing other indicators that are associated with it.

Constructs can be characteristics of individuals, such as intelligence, obesity, job satisfaction, or depression; they can also be broader concepts applied to organizations or social groups, such as gender equality, corporate social responsibility, or freedom of speech.

Example

There is no objective, observable entity called “depression” that we can measure directly. But based on existing psychological research and theory, we can measure depression based on a collection of symptoms and indicators, such as low self-confidence and low energy levels.

What is construct validity?

Construct validity is about ensuring that the method of measurement matches the construct you want to measure. If you develop a questionnaire to diagnose depression, you need to know: does the questionnaire really measure the construct of depression? Or is it actually measuring the respondent’s mood, self-esteem, or some other construct?

To achieve construct validity, you have to ensure that your indicators and measurements are carefully developed based on relevant existing knowledge. The questionnaire must include only relevant questions that measure known indicators of depression.

The other types of validity described below can all be considered as forms of evidence for construct validity.

Content validity

Content validity assesses whether a test is representative of all aspects of the construct.

To produce valid results, the content of a test, survey or measurement method must cover all relevant parts of the subject it aims to measure. If some aspects are missing from the measurement (or if irrelevant aspects are included), the validity is threatened.

Example

A mathematics teacher develops an end-of-semester algebra test for her class. The test should cover every form of algebra that was taught in the class. If some types of algebra are left out, then the results may not be an accurate indication of students’ understanding of the subject. Similarly, if she includes questions that are not related to algebra, the results are no longer a valid measure of algebra knowledge.

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Face validity

Face validity considers how suitable the content of a test seems to be on the surface. It’s similar to content validity, but face validity is a more informal and subjective assessment.

Example

You create a survey to measure the regularity of people’s dietary habits. You review the survey items, which ask questions about every meal of the day and snacks eaten in between for every day of the week. On its surface, the survey seems like a good representation of what you want to test, so you consider it to have high face validity.

As face validity is a subjective measure, it’s often considered the weakest form of validity. However, it can be useful in the initial stages of developing a method.

Criterion validity

Criterion validity evaluates how closely the results of your test correspond to the results of a different test.

What is a criterion?

The criterion is an external measurement of the same thing. It is usually an established or widely-used test that is already considered valid.

What is criterion validity?

To evaluate criterion validity, you calculate the correlation between the results of your measurement and the results of the criterion measurement. If there is a high correlation, this gives a good indication that your test is measuring what it intends to measure.

Example

A university professor creates a new test to measure applicants’ English writing ability. To assess how well the test really does measure students’ writing ability, she finds an existing test that is considered a valid measurement of English writing ability, and compares the results when the same group of students take both tests. If the outcomes are very similar, the new test has a high criterion validity.

Is this article helpful?
Fiona Middleton

Fiona has been editing for Scribbr since August 2016. She has a bachelor's degree in geology and is currently working towards a master's degree in marine sciences. She loves working with students based around the world to refine their writing.

14 comments

Pronay sen
October 16, 2020 at 5:15 PM

Very nicely explain the validity of a test ... quite impresive !

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Ben
October 14, 2020 at 7:59 AM

This is beautiful.

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Ihsan
October 19, 2020 at 11:14 AM

Very useful and has been explained in a simple way.

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DR. SYED TAHSEEN HAIDER KAZMI .
September 28, 2020 at 12:48 PM

I am quite impressed by the explanation of different types of validity. Construct validity is most important which tells us whether we are able to correctly measure what we are supposed to measure. In Quantitative research, validity has two components Sensitivity and Specificity. I think Construct validity is close to the concept of sensitivity. Content validity is more related to comprehensiveness in the measurement of your construct i.e. your exam is able to measure all components of the concept or construct. Criterion validity is a comparison of your scale with an existing benchmark through correlation. Excellent work to explain this difficult concept.

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ES Chew
September 5, 2020 at 10:48 PM

Hello Shona,
First of all, thanks for your helpful website on clarifying the different types of validity.

I am doing research with the aim of designing, developing, and testing a basic creativity module. I'll like to get a 2nd opinion on the types of validity associated with the module development.
As I know there are 3 areas where validity is involved namely,
I) creative content (content validity)
II) module design & formatting (face validity or content validity??)
III) clarity of language used (face validity)

I am quite sure about I) and III) but uncertain about II)
Hope you can help.
Thanks.

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Kheni Mb
August 25, 2020 at 6:41 PM

Thanks a bunch. This has been so, so helpful.

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Rita
June 23, 2020 at 3:28 PM

Good job done. Kudos to the writer.

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Ask a question
June 17, 2020 at 8:18 AM

How do I cite the information above if i want to use it?

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Shona McCombes
Shona McCombes (Scribbr-team)
June 25, 2020 at 8:36 PM

Hi,

The citation for our articles depends on the citation style you are using, but you should usually include the author's name (in this case, Fiona Middleton), the title of the article ("The four types of validity"), the website name (Scribbr), and the publication date (September 6, 2019). See our guide to citing a website in APA, MLA, or Chicago to check the exact format.

Hope that helps!

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Cliff
June 3, 2020 at 5:17 PM

Absolutely clear thanks!

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Abdullah Mir
January 19, 2020 at 9:32 PM

content is written with such a clarity and simplicity.It is very easy to understood and remember.Thank you.

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Nuristani
December 16, 2019 at 1:18 PM

It is very precise, practical and to the point. Thanks for sharing

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Chadia
December 9, 2019 at 11:47 AM

What is methods of collecting data ??

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Shona McCombes
Shona McCombes (Scribbr-team)
December 23, 2019 at 12:31 PM

Hi Chadia,

Data collection methods are used to get the information you need to answer your research question. That might include things like surveys, observations or experiments. You can read more in our introduction to research methods.

Hope that helps!

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