[GRASS-dev] terminology issues in grass7

[Roger Miller]

I've not responded on-list for a while now, but this thread touches on
something that has bothered me for a while.

I'm an advanced user, but I'm still using 6.3.  Have subsequent releases
changed the use of "layer" in 6.0 through 6.3?  I recall that in those
cases, a "layer" in the vector apps referred to a database table, and
not to anything with a graphical representation.  If that has been
already fixed, then perhaps the term "layer" can be used for something
else, but it shouldn't be used at all unless the former uses have been
removed.

I prefer terminology in which the word "map" refers to a graphical
representation of geospacial data.  The map may be simple or complex,
printed or on-screen.  If I can look at it and see spacial relations
then it is a map.  That graphical representation can be composed of one
or more than one set of geospacial data.  A single raster data set may
comprise a map, or a map may (and often does) include representations of
many sets of geospacial data, plus decoration and annotation.

In conversations with my peers I usually try to avoid using the term
"layer" for any kind of GIS entity.  The term provides a handy mental
image, but it is also a term widely used for other purposes.  I often
use GRASS to support ground water models that have layers of their own.
The "layer" terminology becomes confusing.  I believe there are other
applications where the term presents potential confusion.

For most of my uses, I refer to the data components of a map as "data
sets."  If you need to distinguish between the spacial data and the
tabular data associated with it then the modifications are simply
"spacial data sets" and "tabular data sets."  


Roger
 
On Fri, 2009-06-12 at 13:08 -0700, Michael Barton wrote:
> On Jun 12, 2009, at 12:37 PM, Martin Landa wrote:
> 
> > Hi,
> >
> > 2009/6/12 Michael Barton <Michael.Barton at asu.edu>:
> >
> > [...]
> >
> >> From this perspective, data layers seems sensible and I even talk  
> >> about
> >> geospatial data when I teach GIS. I also understand the cartographic
> >> perspective that maps are the final, often paper, result of combining
> >> multiple geospatial data layers. Nonetheless, most users will find  
> >> it less
> >> confusing if we just continue to call them maps--with the idea that  
> >> we've
> >
> > Which users? The users who I know are confused by "map" in the context
> > that is used in GRASS. I remember when I started to use GRASS as my
> > first GIS - I didn't understood why I should call raster file as
> > "map". Probably my feeling is too much cartographic one - map is some
> > kind of composition with given layout, decorations, text labels, etc.
> > When I display raster file/dataset/layer or whatever in GRASS, e.g.
> > 'elevation' from spearfish location, it's not a map in my eyes. I
> > think that 'map' in this context is not right and whatever would be
> > better. Sorry probably to much radical this evening;-)
> 
> Well, in part this may be a US perspective, but it is also an intro  
> versus advanced user perspective. Intro GIS texts here (e.g., Clark or  
> Heywood, Cornelius, & Carver) tend to talk about maps. More advanced  
> texts (and perhaps more European texts) seem to talk more about data  
> layers and spatial data (e.g., Burrough & McDonnell). In fact, what we  
> are using are spatial database files (or tables if in something like  
> PostGIS) and so data or spatial data are more accurate technical  
> terms. But these data are formatted/constructed so that they directly  
> translate into something that is visually very akin to a paper map.
> 
> I'm usually teaching beginning GIS users, so I've always found GRASS's  
> "maps" easy to to get across (and say in English and Spanish: mapas  
> vs. datos espaciales). However, I really don't have a problem with  
> switching to spatial data or something like that if we want to be more  
> technically correct.
> 
> >
> >> moved maps from paper to digital media. Note that this was the  
> >> original
> >> usage in one of the world's oldest GIS systems still in use (i.e.,  
> >> GRASS).
> >> And looking at the 1980's video that someone rediscovered, the  
> >> parallels
> >> between paper maps and digital maps were made so that potential  
> >> users could
> >> better understand a GIS. From a personal perspective, I really  
> >> don't mind
> >> data layers at all. I just think that map is easer for most users to
> >> understand even if it seems somewhat inaccurate from a more technical
> >> perspective.
> >
> > OK, anyway I still think that we should find more accurate term then
> > the current one. GRASS7 is good occasion (it takes time, and many
> > users will be confused for the short period).
> 
> I agree
> 
> Michael
> 
> >
> > Martin
> 
> 
> ______________________________
> C. Michael Barton, Professor of Anthropology
> Director of Graduate Studies, School of Human Evolution & Social Change
> Director, Center for Social Dynamics & Complexity
> Arizona State University
> Tempe, AZ  85287-2402
> USA
> 
> voice: 480-965-6262; fax: 480-965-7671
> www: http://www.public.asu.edu/~cmbarton
> 
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