I'm a programmer, with a decent but not-expert knowledge of stats, and I'm working through these instructions for how to create funnel plots.
I know that there are better ready-made tools (e.g. R) for generating funnel plots, but these instructions are helping to understand the basics of funnel plots.
So, my question: Step 4 in the instructions refers to a 'special kind' of standard error. Why is it special?
And, can I validly copy the way standard error is calculated in these instructions to build a funnel plot for any dataset that includes raw population count and raw incident count?