The residual is calculated as Actual value - Predicted value, where Predicted value = predicted group mean + predicted subject (row) mean - predicted grand mean. A residual is positive when the corresponding value is greater than the sample mean, and is negative when the value is less than the sample mean. Each residual is the difference between a entered value and the mean of all values for that group.

Residuals with one-way ANOVA and related tests are simple to understand. The residuals from all groups are pooled and then entered into one normality test. Are the residuals Gaussian? Prism runs four normality tests on the residuals.Both these tests compute a P value designed to answer this question:If the populations really have the same standard deviations, what is the chance that you'd randomly select samples whose standard deviations are as different from one another (or more different) as they are in your experiment? The Brown-Forsythe test and the Barlett test. Prism can test this assumption with two tests. Are the residuals clustered or heteroscedastic? ANOVA assumes each sample was randomly drawn from populations with the same standard deviation.ANOVA assumes a Gaussian distribution of residuals, and this graph lets you check that assumption. The Y axis is the predicted residual, computed from the percentile of the residual (among all residuals) and assuming sampling from a Gaussian distribution. The Y axis is the absolute value of the residual.This lets you check whether larger values are associated with bigger residuals (large absolute value). The X axis is the predicted value (or fitted value), the mean of the replicates of the data (but see below for repeated measures). This lets you spot residuals that are much larger or smaller than the rest. Prism can make three kinds of residual plots. A residual plot helps you assess this assumption. One of the assumptions of ANOVA is that the residuals from that model are sampled from a Gaussian distribution. But ANOVA is really regression in disguise. Many scientists thing of residual as values that are obtained with regression. Prism 8 introduced the ability to plot residual plots with ANOVA, provided that you entered raw data and not averaged data as mean, n and SD or SEM.

One way anova graphpad prism 8