Goodchild and Proctor (1997) – Scale in digital geography

As might be expected, Goodchild and Proctor provide an insightful and lucid evaluation of how conceptions of scale should translate from paper to digital maps, and their analysis remains pertinent in the face of two decades of rapid digital cartographic development. They argue that the representative fraction, as traditionally used by cartographers to represent scale, is outdated for use in digital platforms.

Firstly, I think the representative fraction struggles on a simpler level. In absolute terms, we’d probably find it hard to distinguish 250,000 from 2,500,000, so maybe the large numbers involved with representative fractions would be less preferable to those present in alternatives, such as graphical scales, which visually show the relationship between distances on the map and the real world (as used in Google Maps).

It is interesting to revisit the problems outlined in the paper that have been faced by web map makers. A significant advance in the navigation of scale in digital environments has been in the development of tiled web maps. By replacing a single map image with a set of constituent raster or vector ‘tiles’ loaded by zooming and panning through a user interface, this method facilitates levels of detail that vary with zoom level and position in the map. The appearance and disappearance of certain features (e.g. country names vs town names) has formed another metaphor for scale recognition.

I’m still finding it hard to reconcile the idea of scale as used in everyday language (to represent the range of spatial extents that a phenomena operate within) with its scientific/ GISc definition (as a broader metric for the level of geographic detail, as well as extent). Positional accuracy, resolution, granularity etc are fundamentally important across disciplines, but do they correlate with what people think of when they talk about scale? (sorry Jin)

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