LOJIC has developed a system of on-line metadata that includes data dictionaries, sample views and application documentation, all of which are locally accessible via the LOJIC system network. The LOJIC metadata (LOJICDOC), designed as an addition to the Arc/Info ArcDoc user documentation, represents a local effort at building GIS metadata. LOJIC metadata incorporates key components from the FGDC Content Standards for Spatial Metadata and meets local user needs for concise, standardized documentation. This paper presents the LOJIC approach for the design, implementation and maintenance of local GIS metadata.
Introduction Building, enhancing and maintaining a wide range of GIS databases has been a primary activity of LOJIC staff and users for the past ten years. Building on the results of initial photogrammetric base mapping and cadastral mapping data conversion projects, LOJIC users created a wide variety of thematic database layers designed to support users specific needs. Over time, LOJIC's GIS libraries grew to include layers and databases that ranged from Addresses to Zoning, with many additional covers filling in the middle. This steady, if not rapid, growth in the number and utility of LOJIC databases contributed to a dramatic increase in user demands for more complex AML applications and serious consideration of the effectiveness of tools such as Arcview. More data and more applications very simply resulted in more LOJIC users. New users, and a fair number of veteran users, had little or no knowledge of the location, structure, contents, or even the existence of the various databases available via LOJIC. The need for standard references and descriptions to LOJIC applications and databases, all easily accessible to even the most casual user, was the overriding goal in the development of our on-line LOJICDOC. Of lesser importance was strict adherence to and use of each and every component of the FGDC Standard. We attempted, however, to be thoughtfully eclectic in incorporating key elements of the FGDC Standard that met local needs and best described and documented our local databases. Another important factor that led to the design and implementation of LOJICDOC involved the need for appropriate metadata that could be provided to a growing number of outside users of LOJIC applications and databases. LOJIC is often involved in partnership projects with public and private sector groups, or called upon to provide GIS data or services to support the activities of one of its participant agencies. Consistent and thorough LOJIC metadata that can be readily distributed among other Arc/Info users is often vital to the success of joint GIS efforts. LOJICDOC Design All of LOJIC's on-line help system and metadata were developed using Frame Maker desk-top publishing software, which is also the basis for the Arc/Info on-line help system. This allowed LOJICDOC to be built upon and be accessible through the Arc/Info on-line help, thereby providing LOJIC users with a single on-line source for both Arc/Info references, local metadata and application documentation. Users can easily navigate through the various topics, thematic sections, sample views and metadata contained within LOJICDOC via hypertext links. LOJIC's on-line documentation (LOJICDOC) contains four topics that provide LOJIC users with general information, detailed descriptions and usage instructions on LOJIC tools, applications, system configuration and shared database libraries. The section of LOJICDOC entitled 'LOJIC GIS Libraries' provides a general summary of all LOJIC data libraries as well as detailed and standardized metadata for each library layer.
LOJIC Tools The first topic titled 'LOJIC Tools' provides the user with detailed explanations on what a LOJIC tool is and how the tool is accessed and applied in an application. By providing information on LOJIC tools, we hope to minimize application development time and reduce the amount of redundant coding. All tools are stored in the $LOJICTOOLS directory accessible to all users, and adhere to local standards for coding and internal documentation. The directory is further organized into subdirectories (Generic, ARC, ARCPLOT, ARCEDIT, etc.). The LOJIC tools are listed within LOJICDOC under their respective subdirectories with a brief description of the tools' function. Publishing of LOJIC tools is accomplished through local E-mail sent to all members of our AMLPROGRAMMER mail alias, and via user documentation included in LOJICDOC. Individual LOJIC tool headings are also hyperlinked to their individual coding to provide the user a more in-depth explanation on the overall functionality of the tool. LOJIC Applications The second topic in LOJICDOC is entitled 'LOJIC Applications' and consists of hypertext links to detailed user instructions and technical documentation for a number of menu-driven custom applications developed by LOJIC staff. The user documentation provides step-by-step instructions on running an application. The technical documentation provides detailed information on specifications, goals, AMLs and variables used in the application. This provides our users with a standard reference to a growing number of published applications that may be used as is or easily adapted to meet specific user needs. Applications that are currently available system-wide to LOJIC users and documented in LOJICDOC include: BLOCKPLOT, an interface for generating standard block plots of PVA parcel data; BOARDMAP, an interface for generating standard project site maps for MSD Board meetings; BOEPLOT, an interface for generating standard maps of all political jurisdictions as maintained by the County Board of Elections; DE, a generic data editor interface based on ARCEDIT; GQI, a widely used theme-based ARCPLOT interface for data query, browsing, plotting; PE, a menu-driven editing application used by PVA in maintaining the land parcel database; PQMP, an address-based data browser that allows land parcels to be located and plotted along with a wide range of other LOJIC map data; QCR, an interface for performing and reporting database validity and quality control specifications; STREETCL EDITOR; a customized variation of DE used in the maintenance of the county-wide street centerline/address range database. LOJIC System Configuration Information on the LOJIC system configuration was included in LOJICDOC in response to the growth and development of the LOJIC user community. This topic, while currently incomplete, will include information on database backup policy, special system scripts, instructions on the use of LOJIC user group E-mail, system addresses for printers and plotters, schematic diagrams of all LOJIC LAN's, and a master directory of the entire LOJIC user group. Below is a schematic drawing of the first three topics in LOJICDOC. The schematic also shows the hypertext link pathways set in frame.
LOJIC GIS Databases The fourth topic, 'LOJIC GIS Libraries', is the most voluminous section of LOJICDOC. LOJICDOC includes descriptions and dictionaries for all LOJIC database libraries. It incorporates key components from the FGDC Content Standards for Spatial Metadata and meets local users needs for concise, standardized, easily accessible database documentation. LOJIC developed a database documentation template form as the standard for recording the general description, characteristics, maintenance status, points of contact and feature attribute tables and data dictionaries for each of our published databases. Most items in the template are self- explanatory, while others require interpretation and descriptive input from the authors of the various databases. The following guidelines were provided to assist users in standardizing the information recorded on the database documentation template. Also included are examples illustrating the format and method this information is displayed in LOJICDOC. The Municipal boundaries (MB) layer from LOJICDOC is used as the reference. A. General Database Characteristics 1. Database name: Layer or file name (i.e., MB, CN, AMF, etc.) 2. Common name: Descriptive name of data (i.e., Municipal Boundaries, Contours, Address Master File, etc.) 3. Location: Library name or full pathname (i.e., library JEFFCO, library PTD, $LOJICDATA/ info!ARC!AMF) 4. Theme: The database documentation in LOJICDOC will include a summary section that classifies each database by theme. Many of our databases may be classified into more than one theme. At this time, however, all LOJIC databases should fall into one of the following thematic categories: Planimetrics Political Districts Topographics Demographics Property Transportation Addresses Sewers Hydrology Soils Reference Grids Administrative Districts 5. Type(s): Layer or INFO file 6. Class: All appropriate ARC/INFO feature classes contained in the database. 7. Precision: Single or double 8. Geographic Extent: Most of our databases are "county-wide", others have limited extents. 9. Database size: The size of the actual database in 10. Usage limitations: Brief description of any circumstances or characteristics that may limit the use of the database. Data may be appropriate only for limited scales or for overlay and analysis purposes and not large scale cartographics.
B. Database Description 1. Description: Brief description of the database, its contents and general attributes (i.e. MB - "Polygon coverage of all classes of cities in Jefferson County; polygons have attributes for city names, class and codes; arcs have COGO attributes for future use"). 2. Source: The original source from which the database was created (i.e., aerial photography, PVA block maps, SCS soil survey, Planning Commission Address Master File, etc.) 3. Scale: Scale (in feet) at which the graphic data was compiled; not applicable for INFO databases. 4. Author agency: LOJIC user agency responsible for creating the database. 5. Conversion procedures: Description of processes used to create or convert the database into Arc/Info. 6. Intended use: Applications, functions and users the database was initially designed to support.
C. Database Status 1. Status: Current maintenance status of the database i.e. preliminary, design, final, revision. 2. Data date: Date of database creation. 3. Release date: Date of database publication. 4. Maintenance frequency: Database maintenance schedule, if known. Most databases reflect ad hoc corrections; others such as properties are updated daily. 5. Latest revision: Date of latest database revision. 6. Maintained by: The LOJIC user agency responsible for maintaining or updating the database; often different than the author agency. 7. Comments: Used to further explain or describe special conditions regarding database status, maintenance, etc.
D. Point Of Contact 1. Point of Contact: Name, mailing address, phone, E-mail of LOJIC user who serves as primary contact for specific information about the database.
E. Feature Attribute Tables 25. FAT's/Data Dictionaries: List of all FAT's or related INFO files to show item names and definitions; also includes a complete listing, description and domain of all unique attribute codes.
In addition to detailed database descriptions, LOJICDOC also incorporates hypertext links to sample views of individual Arc/Info layers. This was incorporated into LOJICDOC to provide users with a quick, standard visual representation of each LOJIC layer. Sample views of each layer were created using simple ARCPLOT AML's, saved as SUN raster files from screen snapshots, and then imported as FRAME documents into appropriate LOJICDOC subdirectories.
Below is a schematic drawing of the LOJIC GIS Libraries in LOJICDOC. The schematic also shows the hyperlink pathways set in frame.
Conclusion Maintaining database and application documentation in LOJICDOC has become an integral support activity to LOJIC users. Databases and applications are not published on the LOJIC GIS until all appropriate technical and user documents that meet internal standards have been incorporated into LOJICDOC. This requirement has provided many opportunities for LOJIC staff to work directly with local users to establish local guidelines for database and application development, publication and documentation. The on-line LOJICDOC quickly evolved into the authoritative user reference to the LOJIC GIS and totally eliminated the need for binders of hardcopy documentation that all too quickly became outdated. Incorporating LOJICDOC into the on-line Arc/Info help system provided LOJIC users with a single, user-friendly mechanism for perusing not only information specific to the LOJIC GIS, but to Arc/Info software. Even though our users have come to rely on LOJICDOC, it is admittedly less than the ideal documentation tool. It lacks the automated description of internal file structure and feature table item definition as with the Arc/Info DOCUMENT command. LOJICDOC consists of multiple FRAME documents stored in a logical file structure. None of these documents are directly connected to any of the databases they are designed to describe. This requires special effort to provide either CD's of the entire LOJICDOC file structure or printouts of individual documents to outside users of LOJIC GIS databases or applications. LOJICDOC is an imperfect, but useful, first effort at implementing metadata procedures and standards for our local GIS user community. While it draws on key components of the FGDC standards, LOJICDOC was designed first and foremost to support the documentation needs of our local users.