[GRASS-dev] terminology issues in grass7

[Michael Barton]

On Jun 11, 2009, at 11:59 AM, grass-dev-request at lists.osgeo.org wrote:

> Date: Thu, 11 Jun 2009 20:36:18 +0200
> From: Maciej Sieczka <msieczka at sieczka.org>
> Subject: Re: [OSGeo-Discuss] Re: [GRASS-dev] terminology issues in
> 	grass7
> To: Micha Silver <micha at arava.co.il>
> Cc: OSGeo Discussions <discuss at lists.osgeo.org>,	grass-dev list
> 	<grass-dev at lists.osgeo.org>,	Helena Mitasova <hmitaso at unity.ncsu.edu>
> Message-ID: <4A314EA2.8000306 at sieczka.org>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Micha Silver pisze:
>> Martin Landa wrote:
>
>>> map -> layer (Map Layer)
>
>> Yes, that sounds right to me. A map in other GIS context is the final
>> product of many overlapping "layers". I'd like to see that change
>> propogated to both raster and vector.
>
> I'm all for this. A "map" is a graphic representation of geographic
> features (contained in GIS vector and raster data layer(s)) +  
> additional
> information like scale, north arrow and decorations. Say ps.map  
> output.
> Using the term "map" in GRASS for what is commonly reffered to as
> "layer" is against the common sense IMHO.
>
>>> layer -> catset (Category Set)
>
>> This change does not remove the confusion.  The concept of "layer" is
>> explained both on the vectorintro wiki page [1], and in the manuals  
>> as
>> database links. If that's what it is, that's what it should be  
>> called.
>> So layer might become "data link" or  "attribute link"
>
> A "layer" is not a link between a db and GRASS vector map - you can  
> have
> a vector map with multiple layers, neither of which, or only some,  
> being
> connected with a db table. "layer" is indeed merely a set of  
> categories.
> If we change "cat" to "key", maybe "keyset" would be OK?
>
>> And what will the term "cat" be changed to?? I still like Michael
>> Barton's  suggestion [2] of cat being renamed "key" (or "id")
>
> "id" is already used in lower-level vector feature identification (see
> e.g. v.edit help). "key" sounds fine IMHO.
>

I probably shouldn't add more, but I will anyway.

I like calling vector and raster files maps. It is really easy for  
users to understand what these files are. Maps can be added to display  
layers (i.e., like layers in a CAD or drawing package) for display and  
visualization.

The features that are currently called vector "layers" really serve a  
database function. Given that, my preference is that they be called  
something in database jargon that is also very easily recognizable.  
AFAIK, the term "layer" is not a term commonly used for DBMS files and  
functions. The closest common term for what our "layer" does is a key  
field. Whether or not the key field is use to connect the vector to an  
attribute table, that is what it is good for ultimately. So that is  
why I favor some version of "key" for this feature.

FWIW, I always thought that "theme" was a poor choice in terminology  
for a display layer in ESRI. This is an example of something that  
makes some sense from an abstract perspective, but makes for a more  
difficult user experience in actual practice.

Michael