[1] In order to best conceptualize the significance of the data structure for GIS, it is helpful to consider the following hierarchy of definitions adapted from Donna J. Pequet's "A Conceptual Framework and Comparison of Spatial Data Models," Cartographica, Vol. 21, pages 66-113 in Dr. Duane F. Marble's "The Concept of the Data Model" in Module D, "Data Management within the GIS" of Principles of Geographic Information Systems:

Reality: The phenomenon as it actually exists including all aspects which may or may not be perceived by individuals.

Data Model: An abstraction of the real world that incorporates only those properties thought to be relevant to the application or applications at hand, usually a human conception of reality.

Data Structure: A representation of the data model often expressed in terms of diagrams, lists, and arrays designed to reflect the recording of the data in computer code. The data structure is built upon the data model, and details the arrangement of the data elements. This structural arrangement is the heart of the GIS storage and retrieval subsystem.

File Structure: The physical representation of the data in storage hardware. This representation is usually predetermined by the makers of the GIS software and is not usually under the control of the user.

In the hierarchy of definitions presented above, there is a meaningful perceivable gap of information as one attempts to capture reality in a data model. The user's insight and experience is important to define the data model. Many perceptions of reality are lost as one attempts to quantify and represent the information. This representation of the data model involves the selection of the spatial entities and their aspatial attributes. Such selection and arrangement of such spatial data is the key to any GIS.

[2] ESRI White Paper Series, "Enterprise GIS: Using GIS in the Corporate Environment", May 1993, page 11.

[3] David Rhind, Teresa Connolly, and Birkbeck College, University of London, Understanding GIS--The ARC/INFO Method, 1992, pages 1-5.

[4] Id.

[5] Id.

[6] ESRI White Paper Series, "Enterprise GIS: Using GIS in the Corporate Environment", May 1993, page 12.

[7] Id.

[8] Id. at 10

[9] Id.

[10] Matthew D. Bunker, Sigman L. Splichal, Bill F. Chamberlin and Linda M. Perry, "Access to Government-Held Information in the Computer Age: Applying Legal Doctrine to Emerging Technology," in 20 Florida State University Law Review 546 (1993), note 21 citing Leonard W. Levy, Emergence of a Free Press, 250-81 (1985); Vincent Blasi, "The Checking Value in First Amendment Theory, 1977 Am. B. Found. Res. J. 523; Justice Black and First Amendment "Absolutes": A Public Interview, 37 N.Y.U. L.Rev 549 (1962) (transcript of interview conducted by Professor Edmond Cahn).

[11] Id. note 22 citing William J. Brennan, Jr. "The Supreme Court and the Meiklejohn Interpretation of the First Amendment," 79 Harv. L. Rev. 1, 11 (1965).

[12] Id. note 9 citing James Madison, Writings of James Madison 398 (1806), reprinted in "Note, Access to Official Information: A Neglected Constitutional Right," 27 Ind. L.J. 209, 212 (1952).14

[13] Id. note 10 citing Thomas Jefferson, "Letter from Jefferson to Edward Carrington, Jan. 16, 1787, in The Papers of Thomas Jefferson 48-49).

[14] Id. note 11.

[15] 5 U.S.C. Section 552 (1988).

[16] Bunker, Splichal, Chamberlin, and Perry, previous cite, note 83.

[17] Id. note 84 citing NLRB v. Robbins Tire & Rubber Co., 437 U.S. 214, 242 (1978).

[18] Id. note 88 citing Section 552(b)(1)-(9).

[19] Id. note 86 citing 5 U.S.C. Section 552(a)(3) which provides:

Except with respect to the records (mandated to be) made available under paragraphs (1) and (2) of this subsection, each agency, upon any request for records which (A) reasonably describes such records and (B) is made in accordance with published rules stating the time, place, fees (if any), and procedures to be followed, shall make the records promptly available to any person.

[20] Id. note 90 citing Act of January 8, 1988, Pub. L. No. 100-235, 101 Stat. 1724 (1988).

[21] U.S. Copyright Act, 17 U.S.C. Section 102 (b).

[22] Nancy Obermeyer, Indiana State University, at the URISA '94 Conference in Milwaukee, Wisconsin, August 10, 1994.

[23] Senate Report on the 1976 Copyright Act, Section 105. U.S. Government Works, November 20, 1975.

[24] Id.

[25] Melville B. Nimmer and David Nimmer, Nimmer on Copyrights, Volume I, Section 1.03 (A), pages 1-4.22-23 (1994) citing Sony Corp. v. Universal City Studios, Inc., 464 U.S. 417, 429 (1984) "It is intended to motivate the creative activity of authors and inventors by the provision of special reward, and to allow the public access to the products of their genius after the limited period of exclusive control has expired."

[26] Id. citing Fox Film Corp. v. Doyal, 286 U.S. 123, 127 (1932); Twentieth Century Music Corp. v. Aiken, 422 U.S. 151, 156 (1975) ("Creative work is to be encouraged and rewarded, but private motivation must ultimately serve the cause of promoting broad public availability of literature, music, and the other arts. The immediate effect of our copyright law is to secure a fair return for an 'author's' creative labor. But the ultimate aim is, by this incentive, to stimulate artistic creativity for the general public good."); American Int'l Pictures, Inc. v. Foreman, 400 F. Supp. 928 (S.D. Ala. 1975) (Treatise quoted), rev'd, 576 F.2d 661 (5th Cir. 1978). See also Berlin v. E.C. Publications, Inc., 329 F.2d 541 (2d Cir. 1964).

[27] The House Report on the Copyright Act of 1976, Section 105. U.S. Government Works, 122 Cong. Rec. H 10727-8, Sept. 21, 1976.

[28] Id.

[29] Vice President Al Gore, Report of the National Performance Review, "From Red Tape to Results: Creating a Government that Works Better and Costs Less," September 7, 1993.

[30] Id.

[31] Id.

[32] Nancy Tosta, "The National Spatial Data Infrastructure: Where are We Now?", page 25, Geo Info Systems, Jan. 94.

[33] Office of Management and Budget, OMB Circular A-130, "Management of Federal Resources," June 25, 1993.

[34] Id.

[35] Office of Management and Budget, "Management of Federal Information Resources; Notices," Part V, Federal Register, Vol. 59, No. 141, page 37924. Monday, July 25, 1994.

[36] Id.

[37] Id.

[38] Id.

[39] Id.

[40] OMB Circular A-130,previous cite.

[41] Id.

[42] Id.

[43] Id.

[44] Id.

[45] Id.

[46] Id.

[47] Nancy Tosta, previous cite, page 25. ,p. [48] The NRGIS library currently contains 384 ARC coverages in export format available over the Internet. The Iowa NRGIS library has seven main directories, used for READ ONLY:

IOWA Miscellaneous coverages covering the entire State

REGIONIA Miscellaneous coverages covering four large subdivisions of the State

RIVER100 1:100,000 scale rivers by county (from EPA RF3 files)

ROADS100 1:100,000 scale roads by county (from TIGER Line files)

TOPO100 1:100,000 scale metric surface elevation contours by county (from USGS DLG files)

MINES Mine coverages (only coal mines currently available)

PLSS24 1:24,000 scale Public Land Survey System (sections) by county

The Iowa NRGIS library also has several useful README files which are helpful to know before transferring data:

INDEX.TXT A list of coverages in each directory and a short description of each coverage.

DOCUMENT.TXT A short explanation of each of the fields used in the coverage documentation files.

HOW_TO.TXT A short description of the compressed tar files (.taz) and how to decompress them.

IOWA_GIS.TXT A short description of the Iowa DNR's GIS program and the NRGIS Library.

ACCURACY.TXT An explanation of how the positional accuracy assessment was done for each coverage

REGISTER.TXT An optional data user registration form.

WHATSNEW.TXT What is new on the ftp server.

This server is maintained by the Iowa Department of Natural Resources, Energy and Geologic Resources Division, Geological Survey Bureau, Geographic Information Section. Our mailing address is Iowa DNR, Geological Survey Bureau, 109 Trowbridge Hall, Iowa City, Iowa 52242-1319, general phone 319-335-1575, fax 319-335-2754.

If you have questions about Iowa DNR's GIS program, please call Bernie Hoyer, Supervisor, Geographic Information Section, 319-335-1571 [bhoyer@gsbth-po. igsb.uiowa.edu] or Kevin Kane, IDNR GIS coordinator, 515-281-5815 [klkane@aol.com]. If you have problems, questions or comments about this service, please call or E-mail Jim Giglierano, research geologist, 319-335-1594 [jgiglierano@gsbth-po.igsb.uiowa.edu] or Joost Korpel, research geologist, 319-335-1353, [jkorpel@gsbth-po.igsb.uiowa.edu].)

The NRGIS Library FTP server resides on an AST PREMIUM 486/33TE (gsb.igsb.uiowa.edu 128.255.131.1) running Novell Netware 3.11. The .doc files are basically ASCII DOS files. Although digital communication links between DNR field office sites are not completely established, Internet connections are available to DNR's Iowa City office. 49 NRIS Fiscal Year 1993 Annual Report, page 1. To realize this mission and be responsive to user information needs, NRIS has established additional services including the Montana Natural Resource Index, the Montana Natural Heritage Program, the Montana Water Information System, and the NRIS Geographic Information System. The products of all of these programs are publicly accessible via the Montana State Library, and, increasingly, are accessible via the Internet (HTTP://NRIS.MSL.MT.GOV.).

[50] Id.

[51] One database, the Montana Rivers Information System (MRIS), is a unique database that includes cultural features for over 3,500 stream reaches, and information on fisheries, wildlife, recreational, natural, and geologic features. Public access to these data and other data files, including several federal databases, is freely available via the State Library and via a State Bulletin Board. Another project under development, the Ground Water Atlas, includes information on public drinking water supplies and underground fuel tanks. As with other NRIS resources, GIS coverages found in the Atlas are freely available to the public in the Montana State Library.

[52] NRIS, Fiscal Year 1993 Annual Report, previous cite, page 33.

[53] Patricia M. Brown, Indian River County Property Appraiser's Office, Vero Beach, Florida at the URISA '94 Conference in Milwaukee, Wisconsin, August 8, 1994.

[54] Pamela J. Butler, Florida URISA, at the URISA '94 Conference in Milwaukee, Wisconsin, August 9, 1994.

[55] Id.

[56] Pamela J. Butler and Tony Leno, Florida URISA, at the URISA '94 Conference in Milwaukee, Wisconsin, August 9, 1994.

[57] Jeffrey Anderson, City of Snohomish, Everett, Washington, at the URISA '94 Conference in Milwaukee, Wisconsin, August 10, 1994. ,p.