NRGIS Library Metadata Standard
Adopted January 1, 2004

Introduction
This is a standard for metadata documents submitted for publication on the Iowa DNR's Natural Resources Geographic Information Systems Library at 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. 

Requirements
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 http://www.fgdc.gov/metadata. 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 here.

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 tools.

Mandatory Information
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.

• Abstract  (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 some thought.
• 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 Appendix A.
• 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 here.
• Use Constraints (idinfo/useconst). Are there uses that the data should be restricted to or discouraged from?
• 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".

Appendix A:

Sourcing

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.

• Sourcing Guidelines  - A Good document from the State of Louisiana

Appendix B:

Positional Accuracy Assessment

• Accuracy Assessment Paper by Jim Giglierano
•  FGDC - Geospatial Positioning Accuracy Standards, Part 3:  National Standard for Spatial Data Accuracy

Appendix C:

Theme Keywords

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.