ANOVA is to partition the variation among all the observations into different components. One component is due to the variation among the different groups of the factors in the model, which represents signal; another component is due to the variation within groups, which represents noise (it is also called error, because it is the variability that is not explained by any factors ).  F-statistic is a ratio of the two components, that is signal vs noise ratio

F = Between group variance / within group variance

Large F value of a factor indicates between group variation is large relative to the within group variation, which results in a small p-value. On the other hand, small F value of a factor indicates the between group variation is small relative to the within group variation, which results in a big p-value.

In Partek^® Flow^®,  source of variation plot is using bar chart to show F ratio of each factor in the ANOVA model relative to the error. It is available on ANOVA report, click on the icon   to invoke the plot to exam the variation contribution of all the factors in the ANOVA model relative to the within group variation (an example plot is on Figure 1).

 

Figure 1. Source of variation plot

The chart title is based on the feature (e.g. gene or transcript) that the plot was invoked on. The y-axis is F value, X-axis represent the factors specified in ANOVA model as well as Error term which will have the F value as 1 (since error is the denominator, so F value would be 1).

Plot controls are in the panel on the left. The <Previous and Next> buttons enable you to switch between genomic features as they appear in the parent Feature list.  The bar colors are controlled by the Customize colors option. If you want to change a color, select the  icon to choose color. 

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