Subject: double bar graphs
Who is asking: Parent
Does she simply graph the year with participants only, or is there some way to show that "zero" were in the other year? I can't seem to find that addressed anywhere!
You certainly need to somehow indicate the "zero". There is no standard way to present a double bar graph or even a bar graph but I hope that my diagrams help.
First, if possible, I would present the graph so that it is clear there is something "missing". To be specific I would draw
In the first diagram it is clear that something is missing between the first two red bars.
I haven't put any labels on the diagram but you should label them. I expect that the text or the teacher have a prefered way to label the axes. Sometimes you see a number below each bar to indicate its height. If so you can put a "0" below the missing bar. Otherwise you may need a footnote. For example:
I am sorry that I can't be more specific as there is no standard way to present a bar graph.Cheers,