Some Initial Concerns

Mon May 1 15:33:37 2000

A comment by Robert H. Fakundiny about

Some generic issues to consider

by Jonathan C. Matti

Dear Jonathon and Team,
I'm sorry to be getting into this discussion so late, but I've been away or
occupied for the last few weeks.  Before  jumping into this murkey pool of
issues, I would like to comment on a few items that has plagued my staff
regarding "digital data bases."  The first Guiding Principle states that
"(t)he SLTT's focus is digital geologic-map data bases-NOT geologic maps.  I
cringe, because common usage among non-geologist data-base experts is that
"geologic map"="data base."  They do not realize, nor care (for most of
them) that geologic maps, commonly are representations by mappers of their
hypotheses about the nature (distribution, composition, form, etc.) of the
earth materials they are mapping that are based upon sparce data points in a
spatial context with many boundaries hypothesized as to type and location by
interpolation and extrapolation.  Geologic maps are interpretations,
interpolations, or guesses that are built upon the mapper's working models. 
Thus, most geologic maps are not only  graphic representations of data or
data bases, but rather, they are the scientist's attempt to portray
imagination and interpretation of the universe between data points.  Many
non-geologists will wish to plot geologic point data in a spatial format to
create a "geologic map", of sorts, without the benefit of the data
collector's experience.  Many will then want to compare that map of
imaginary geology with maps of other types of spatial data or
interpretations.  Commonly, the bases are not compatible, so non-geologists
might change scales, stretch, distort, or otherwise change the spatial
relations of the original data set to make the bases compatible and allow
for spatial comparisons.  Therefore, whether we like it or not, we have to
deal with digital geologic map issues, if only because non-geologists do not
appreciate the tenuous nature of geologic maps and their limited uses.

An incomplete list of map issues includes (1) misuse of scales and scale
changing, (2) data points vs. 2-D or 3-D maps, (3) accuracy of data (and
precision?), (4) formats and comprehensiveness of explanations, (5)caveats
about using data sets and maps for inappropriate purposes, and (6)
classification schemes.  1.  I've already discussed misuse of scales, scale
changing, and base distortion.  2.  I've discussed data points vs. maps.  3.
 Accuracy and precision of data are the purview of the researcher and peer
review.  4.  Formats and comprehensiveness of explanations about data sets
seems to be a major concern for us.  5.  Caveats must be developed to
protect the users and the generators of data sets and ourselves from
physical, financial, and legal harm.  6.  We should stay out of the business
of standardizing classification schemes that are pertenant to the nature of
the data; we should only concern ourselves with classification of formats of
"data sets."  Most researchers will not follow our suggetions anyway.  They
like to modify or create classification schemes as part of their creative
process.  Just as the North American Stratigraphic Code does not classify
sedimentary rock types (it only provides a philosophy for conceptually
packaging or compartmentalizing sedimentary rock strata), we should not
start classifying metamorphic rocks (especially high-grade ones!)

Context of this discussion

This page is part of a discussion of Some generic issues to consider:

Further discussion of Some Initial Concerns (this page):

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