Why use ANOVA instead of multiple tests when testing means differences between multiple groups?

Why use ANOVA instead of multiple tests when testing means differences between multiple groups?
There is a thin line of demarcation amidst t-test and ANOVA, i.e. when the population means of only two groups is to be compared, the t-test is used, but when means of more than two groups are to be compared, ANOVA is preferred.

T-test and Analysis of Variance abbreviated as ANOVA, are two parametric statistical techniques used to test the hypothesis. As these are based on the common assumption like the population from which sample is drawn should be normally distributed, homogeneity of variance, random sampling of data, independence of observations, measurement of the dependent variable on the ratio or interval level, people often misinterpret these two.

Here, is an article presented for you to understand the significant difference between t-test and ANOVA, have a look.

Content: T-test Vs ANOVA

  1. Comparison Chart
  2. Definition
  3. Key Differences
  4. Conclusion

Comparison Chart

Basis for ComparisonT-testANOVA
MeaningT-test is a hypothesis test that is used to compare the means of two populations.ANOVA is a statistical technique that is used to compare the means of more than two populations.
Test statistic(x ̄-µ)/(s/√n)Between Sample Variance/Within Sample Variance

Definition of T-test

The t-test is described as the statistical test that examines whether the population means of two samples greatly differ from one another, using t-distribution which is used when the standard deviation is not known, and the sample size is small. It is a tool to analyse whether the two samples are drawn from the same population.

The test is based on t-statistic, which assumes that variable is normally distributed (symmetric bell-shaped distribution) and mean is known and population variance is calculated from the sample.

In t-test null hypothesis takes the form of H0: µ(x) = µ(y) against alternative hypothesis H1: µ(x) ≠ µ(y), wherein µ(x) and µ(y) represents the population means. The degree of freedom of t-test is n1 + n2 – 2

Definition of ANOVA

Analysis of Variance (ANOVA) is a statistical method, commonly used in all those situations where a comparison is to be made between more than two population means like the yield of the crop from multiple seed varieties. It is a vital tool of analysis for the researcher that enables him to conduct test simultaneously. When we use ANOVA, it is assumed that the sample is drawn from the normally distributed population and the population variance is equal.

In ANOVA, the total amount of variation in a dataset is split into two types, i.e. the amount allocated to chance and amount assigned to particular causes. Its basic principle is to test the variances among population means by assessing the amount of variation within group items, proportionate to the amount of variation between groups. Within the sample, the variance is because of the random unexplained disturbance whereas different treatment may cause between sample variance.

With the use of this technique, we test, null hypothesis (H0) wherein all population means are the same, or alternative hypothesis (H1) wherein at least one population mean is different.

The significant differences between T-test and ANOVA are discussed in detail in the following points:

  1. A hypothesis test that is used to compare the means of two populations is called t-test. A statistical technique that is used to compare the means of more than two populations is known as Analysis of Variance or ANOVA.
  2. Test Statistic for T-test is:  
    Why use ANOVA instead of multiple tests when testing means differences between multiple groups?
    Test Statistic for ANOVA is:
    Why use ANOVA instead of multiple tests when testing means differences between multiple groups?

Conclusion

After reviewing the above points, it can be said that t-test is a special type of ANOVA that can be used when we have only two populations to compare their means. Although the chances of errors might increase if t-test is used when we have to compare more than two means of the populations concurrently, that is why ANOVA is used

Why use ANOVA instead of multiple tests when testing means differences between multiple groups?

The Best Targeting Option for Achieving Brand Awareness SHARE THE ARTICLE ON Table of Contents What is Brand Awareness? Brand awareness is a marketing term

Read More »

Why use ANOVA instead of multiple tests when testing means differences between multiple groups?

Customer experience is in the spotlight for most companies these days and for good reason – It is the final piece of the equation which

Read More »

Intraclass Correlation Coefficient (ICC) SHARE THE ARTICLE ON Share on facebook Share on twitter Share on linkedin Table of Contents What is a Correlation Coefficient?

Read More »

Why use ANOVA instead of multiple tests when testing means differences between multiple groups?

A Guide to Digital Customer Experience (DCX) in 2022 SHARE THE ARTICLE ON Table of Contents With technology advancing at an exponential rate, businesses that

Read More »

Why use ANOVA instead of multiple tests when testing means differences between multiple groups?

Analyzing Survey Data Voxco is trusted by 450+ Global Brands in 40+ countries See what question types are possible with a sample survey! Try a

Read More »

Why use ANOVA instead of multiple tests when testing means differences between multiple groups?

Research Bias SHARE THE ARTICLE ON Table of Contents What is research bias? When a researcher introduces a systematic error into the sample data, he

Read More »