I have plotted the total consumption (g) of a solution by my experimental organisms. However, when I plotted the error bars (s.e.m) a few crossed zero (see image).

(1) is this correct/plausible?

(2) How should I interpret this?

thanks in advance.

[![Standard-error bar plot][1]][1]

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#### Best Answer

I assume the quantity you are looking at should never be less than zero. Thus, this indicates that with the limited amount of data you have your model is a bit problematic and predicts that values could be below zero. Potential ways of dealing with this could include transformation of the data for analysis. One obvious option is log-transformation (especially if you never observe an actual zero value). If you then back-transform the numbers in each group after analysis, you get a geometric mean (instead of the arithmetic mean) with CIs/error bars that would not overlap zero.

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