NRGIS Library Metadata Standard
Adopted January 1, 2004
This is a standard for metadata documents submitted for publication on
the Iowa DNR's Natural Resources Geographic Information Systems Library
http://www.igsb.uiowa.edu/nrgislibx/ The NRGIS Library is a central
repository for the discovery of Geographic Information System data about
Iowa, and it provides for download or direct access of it's resources.
Metadata is "data about data," in other words, it describes your data so that
other users can understand what your data is about and how to properly use it.
Metadata is required for all data that is going to be included on the NRGIS
Library and DNR Web Mapping Applications.
Metadata documents submitted to the NRGIS Library must be valid XML
documents that conform to the structure set out in the Federal
Geographic Data Committee’s (FGDC) Content Standard for Digital
Geospatial Metadata (CSDGM), version 2.
There is extensive information about the CSDGM at
The web site has links to free and commercial software tools
available to assist publishers in creating FGDC-compliant XML
metadata documents. The FGDC published a workbook describing the
CSDGM, and a copy of this is available from the NRGIS Library
The CSDGM contains information about what metadata elements are
required and optional. For the purposes of the NRGIS Library, the FGDC
standard is a list of elements that are available to fill out. Some
metadata software tools have various levels of enforcement of the
element requirements from the CSDGM. NRGIS Library contributors may
exercise discretion on whether to obey the rules set up by these
The Library managers will review your metadata and
the data it describes. If they feel they do not understand it or if the
following sections are not filled out properly, they may ask you to
provide more information before they publish your metadata.
(idinfo/abstract) is a paragraph or two describing the "who, what,
where, when" of your data. be sure to include general content
and features, data set form (GIS, image, dbase...), geographic
coverage, time period, and special data characteristics or
limitations. This section is very important. Give it
- Originator (idinfo/citation/citeinfo/origin)
is the agency or person primarily responsible for creating the data
set. If, for example, this data was obtained from the Census Bureau
and you made several corrections to the data, you would still
probably list the Census Bureau as the originator. You may enter
multiple originators if you feel this is necessary.
- Theme Keywords (idinfo/keywords) you
must choose, from a defined list, the proper keywords. See
- Source Information (dataqual/lineage/srcinfo).
What documents or data sets did you obtain information for this data
set from? See Appendix B.
- Process Steps (dataqual/lineage/procstep).
What did you do to create the data?
- Entity and Attribute Information (eainfo)
is where you should put a list of the tables and data fields that
come with your data, and explanations of what they contain. Fields
that have a limited domain should have a list of the allowable
values and, if applicable, their meanings.
Other Important Metadata Fields
You are strongly encouraged to fill out these fields. In some cases, the
Library managers may ask you to fill some of these out if they feel an
element from this list is especially important for your data set.
- Purpose (idinfo/descript/purpose)
describes a specific purpose the data was developed for, or
something you want to see other people use it for. You don’t have to
imagine a purpose for the data if you don’t want to put anything
- Use Constraints (idinfo/useconst). Are
there uses that the data should be restricted to or discouraged
- Progress (idinfo/status/progress)
indicates whether the data set can be considered as a finished
product. If the data is constantly being updated, you can still say
it is "complete", as in having all the latest data you know about.
- Update Frequency (idinfo/status/update).
How often is the data updated?
- Completeness Report (dataqual/complete).
Is there some subset of the data that is missing? For example, "No
data is available for Dawson County" or "Streams less than two miles
long have been omitted".
- Attribute Accuracy Report (dataqual/attracc/attraccr).
If there is something you should say about the accuracy of any of
the data’s attribute fields, put it here. For example, "Each well ID
number was independently checked against the source map by two
technicians" or "Standard deviation for Calcium concentration in
control samples was 8 mg/L".
- Horizontal Positional Accuracy Report
(dataqual/posacc/horizpa/horizpar). Tell us what you know about the
accuracy of the coordinates, such as "GPS coordinates were not
differentially corrected, and the receiver reported accuracy values
of between 10 meters and 40 meters during the survey."
See Appendix C.
- Vertical Accuracy Report (dataqual/vertacc/vertaccr).
Describe the accuracy of any elevation information in the data set.
"Elevations were estimated from a topographic map whose contour
interval is 80 feet".
Citing your source data is a very important step in giving
the user information about where the data came from and how accurate it may be.
Positional Accuracy Assessment
Metadata documents for the NRGIS Library must
have a Theme Keyword section that contain a Theme Keyword Thesaurus
whose value is "ISO 19115 Topic Category" and at least one Theme Keyword
whose value is taken from the following list.