What is an ANOVA?

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JoVE Core Statistik
What is an ANOVA?

Nächstes Video10.2: One-Way ANOVA

The analysis of variance—abbreviated as ANOVA —is used when the means of three or more samples need to be tested for equality.

For example, ANOVA can help a consumer select a car after comparing the average fuel consumption of cars from different companies.

The samples used for the ANOVA test should have three essential characteristics or statistical assumptions.

The first assumption is that samples should be drawn from normally distributed populations.

The second assumption is that samples should be selected randomly and independently from the populations.

The third assumption is that populations of samples should have equal variances.

There are two commonly used types of ANOVA tests: one-way ANOVA and two-way ANOVA.

One-way ANOVA is used when samples are defined or categorized by one factor or treatment, and two-way ANOVA is used when samples are defined or categorized by two factors or treatments.

ANOVA has a wide application in life science, forensics, social sciences, and business administration.

What is an ANOVA?

The Analysis of Variance or ANOVA is a statistical test developed by Ronald Fisher in 1918. It is performed on three or more samples to check for equality between their means.

Before performing ANOVA, one must ensure that the samples used for this analysis have three crucial characteristics or statistical assumptions. The first assumption states that the samples should be drawn from normally distributed samples, while the second requires that all the drawn samples should be randomly and independently selected. The third and last assumption states that the samples should be drawn from populations with equal variances.

There are two commonly used types of ANOVA:  one-way ANOVA and two-way ANOVA. One-way ANOVA is used for the samples categorized by one factor, whereas two-way ANOVA is used when two factors categorize the samples.

Further, ANOVA is a helpful method that has broad practical applications. It can help a consumer select a washing machine or refrigerator after comparing different models or help a sociologist discern whether a person's income depends on their upbringing. ANOVA is used in environmental sciences to determine the variation in average pollution levels among several water bodies. Hence, ANOVA is widely applicable in fields such as life science, business administration, social science, forensic science, etc.

This text is adapted from Openstax, Introductory Statistics, Section 13.1 One way ANOVA