Why does Prism not plot some error bars?

Prism can graph error bars either from replicates you enter, or error values (SD, SEM, etc.) you enter. But sometimes, no error bar appears for certain points on XY graphs. The reason is simple. If the error bar would be shorter than the size of the symbol, Prism simply won't draw it, even if the symbol is clear.

To see the error bar, do one of the following:

• Make your symbols smaller.
• Switch from SEM error bars  to SD or range error bars.
• Instead of plotting error bars, plot each replicate.