what are the disadvantages of using chloropleth maps?
a false impression of abrupt change can be given at the boundaries of shaded units
important variations within an area can often not be shown. for this reason smaller units are better than large ones
shading the whole area/state gives an impression of unity that does not always exist
it can be difficult to distinguish between different shades
chloropleth maps aren't suitable for showing total values. proportional overlays can be used as a solution
values chosen for various shades on the map are very significant and may be misleading
