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Attached is a map showing the reporting rate for
Brown Treecreeper from 1981 to 2011.
It illustrates one way to overcome one of the
fundamental problems with reporting rate maps: they do not show how many sheets
contributed to the reporting rate. The basic problem is that the number of
sheets submitted for a gridcell is an important factor in determining the
reliability of the reporting rate. Any species reported on the
only sheet submitted for a gridcell gets a 100% reporting rate for that
gridcell. A gridcell with a reporting rate of zero means little if only one
sheet has been submitted and means nothing if no sheets have been submitted for
the gridcell.
The map indicates the quality of the reporting rate
by the circles in the gridcells. The smaller the circle and the less
obvious the colour, the better the reliability of the reporting rate. Cells with
red circles indicate a very low reliability, yellow is better but the data
should still be used with caution and very small green or clear circles indicate
the best data reliability. The cells with the squares are ones where Brown
Treecreeper has been reported. For instance, the map indicates that around
Gunning is a good place to see Brown Treecreeper (high reporting rate with a
good number of sheets submitted) but B08 may not be as good (it has a high
reporting rate but only one sheet has been submitted).
Gridcells without any sheets have nothing in them
on this map but this needs to be improved to distinguish them more easily from
the 50+ sheets cells. Also the number of categories for the number of sheets
could be changed (eg 0,1-2, 3-10, 10-50, 50+) or reduced.
While I recognise that map is currently overloaded
and the graphic design could be greatly improved, does including a
reliability indicator improve the ability to get useful information off the
reporting rate map?
Steve
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