What is a one-way ANOVA?

One-way ANOVA (analysis of variance) is used to investigate whether or not there are any statistically significant differences between the means of 3 or more unrelated groups. 

One-way ANOVA is the more commonly used of the two types of ANOVA tests. It is used when investigating one quantitative dependent variable and one categorical independent variable or factor. The independent variable must have at least 3 different groups or categories (3 levels). The one-way ANOVA test helps researchers determine if variations or different levels of the independent factor have a measurable effect on the dependent variable. For example, one-way ANOVA can be used to compare the difference in crop yield using different types of fertilizers as the independent variable. The one main limitation of one-way ANOVA is that it is an omnibus statistic. That means it can tell researchers if at least one pair of means is significantly different but it cannot tell researchers which pair is different.