Explorable.com142.8K reads

Repeated Measures ANOVA is a technique used to test the equality of means.

Discover 34 more articles on this topic

Don't miss these related articles:

- 1Statistical Hypothesis Testing
- 2Relationships
- 3Correlation
- 4Regression
- 5Student’s T-Test
- 6ANOVA
- 7Nonparametric Statistics
- 8Other Ways to Analyse Data

It is used when all the members of a random sample are tested under a number of conditions. Here, we have different measurements for each of the sample as each sample is exposed to different conditions.

However, it is used when all the members of a random sample are tested under a number of conditions. Here, we have different measurements for each of the sample as each sample is exposed to different conditions.

In other words, the measurement of the dependent variable is repeated. It is not possible to use the standard ANOVA in such a case as such data violates the assumption of independence of data and as such it will not be able to model the correlation between the repeated measures.

However, it must be noted that a repeated measures design is very much different from a multivariate design.

For both, samples are measured on several occasions, or trials, but in the repeated measures design, each trial represents the measurement of the same characteristic under a different condition.

For example, repeated measures ANOVA can be used to compare the number of oranges produced by an orange grove in years one, two and three. The measurement is the number of oranges and the condition that changes is the year.

But in a multivariate design, each trial represents the measurement of a different characteristic.

Thus, to compare the number, weight and price of oranges repeated measures ANOVA cannot be used. The three measurements are number, weight, and price, and these do not represent different conditions, but different qualities.

Repeated measures design is used for several reasons:

- By collecting data from the same participants under repeated conditions the individual differences can be eliminated or reduced as a source of between group differences.
- Also, the sample size is not divided between conditions or groups and thus inferential testing becomes more powerful.
- This design also proves to be economical when sample members are difficult to recruit because each member is measured under all conditions.

This design is based on the assumption of Sphericity, which means that the variance of the population difference scores for any two conditions should be the same as the variance of the population difference scores for any other two conditions.

But this condition is only relevant to the one-way repeated measures ANOVA and in other cases this assumption is commonly violated.

The null hypothesis to be tested here is:

H_{0}: There are no differences between population means.

Some differences will occur in the sample. It is desired to draw conclusions about the population from which it was taken, not about the sample. The F-ratios are used for the analysis of variance and conclusions are drawn accordingly.

The repeated measures design is also known as a within-subject design.

The data presented in this design includes a measure repeated over time, a measure repeated across more than one condition or several related and comparable measures.

Full reference:

Explorable.com (May 25, 2009). Repeated Measures ANOVA. Retrieved Sep 20, 2019 from Explorable.com: https://explorable.com/repeated-measures-anova

The text in this article is licensed under the Creative Commons-License Attribution 4.0 International (CC BY 4.0).

This means you're free to copy, share and adapt any parts (or all) of the text in the article, as long as you give ** appropriate credit** and

That is it. You don't need our permission to copy the article; just include a link/reference back to this page. You can use it freely (with some kind of link), and we're also okay with people reprinting in publications like books, blogs, newsletters, course-material, papers, wikipedia and presentations (with clear attribution).

Discover 34 more articles on this topic

Don't miss these related articles:

- 1Statistical Hypothesis Testing
- 2Relationships
- 3Correlation
- 4Regression
- 5Student’s T-Test
- 6ANOVA
- 7Nonparametric Statistics
- 8Other Ways to Analyse Data

Thank you to...

This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 827736.

Subscribe / Share

- Subscribe to our RSS Feed
- Like us on Facebook
- Follow us on Twitter
- Founder:
- Oskar Blakstad Blog
- Oskar Blakstad on Twitter

Explorable.com - 2008-2019

You are free to copy, share and adapt any text in the article, as long as you give *appropriate credit* and *provide a link/reference* to this page.