Suppose a biochemist wants to look at the influence of stirring speed and temperature on the outcome of an assay or if a pharmacology researcher wants to determine if there is an interaction between an experimental drug treatment and gender on cytochrome P450 activity. Research questions are often complex and typically involve more than one factor. Using multiple t-tests increases the chances of making a Type I error (incorrect rejection of a true H 0!).

When you are analysing more than two groups, it is strongly recommended to analyse your data using ANOVA instead. The t-test is a robust test for detecting a statistical difference in means between two populations that are normally distributed. Why are multiple t-tests not recommended?

In this article, we will show you how to do one-way ANOVA calculations on Microsoft Excel. The higher this ratio, the weaker the evidence supporting H 0. The calculation of the F-statistic, which is simply the ratio of the variation between sample means to the variation within the samples, is the basis of ANOVA calculations. One-Way ANOVA is also referred to as unifactor ANOVA or single factor ANOVA.

Alternative Hypothesis (H 1): There is a significance difference in the means due to a factor.

Using mathematical expressions, we can express H 0 as: µ 1 = µ 2 = µ 3 … = µ n

Null Hypothesis (H 0): There is no difference in the means due to a factor.

The null and the alternative hypotheses for one-way ANOVA can be stated as follows: One-way ANOVA looks at the effects of one factor. Examples of possible factors include temperature, solvent polarity, catalyst, location, method of analysis, diet or drug treatments. In the context of ANOVA, an influence factor is an independent treatment variable that an experimenter can control and/or vary, which may or may not result in significant differences in means. In graphs and in figures, statistical significance is typically expressed using asterisks (*) and sometimes, authors also state the significance level (α). ANOVA can be used to determine if there is a statistically significant difference between the means of groups, due to some influence factor.

What is One-Way ANOVA? A Short IntroductionĪnalysis of Variance (ANOVA) is a widely used statistical technique in clinical research, pharmacology, psychology, molecular medicine, and other fields of experimental science for analysing data.

Graphpad prism 8 two way anova