Definition of Terms

Included below are definitions of terms used throughout this thesis. Some of the definitions come from "authoritative" sources, others from my own sense of the term's meaning.

ARC/INFO

Created by Environmental Systems Research Institute (ESRI), ARC/INFO is a powerful GIS with many abilities to manipulate and analyze data, but difficult to learn.

AML (Arc Macro Language)

A programming language developing specifically for use with ARC/INFO. This language allows a user to create macros, allowing one to automate tasks that would otherwise have to be repeated manually.

ArcView

Also created by ESRI, ArcView is a desktop GIS. It is less powerful than ARC/INFO, but with a lower price tag and a Graphical User Interface, more easily accessible to the general public.

Attribute data

Descriptive information stored in a database about features located on a map.

Coverage

A digital version of a map containing both geospatial coordinates and attribute data.

Digitized map

A map converted to digital form by using a mouse-like digitzing device to record the spatial coordinates of map features. (Huxhold, Glossary)

Geospatial data (aka spatial data)

Information that is related to a location. It is estimated that 70% of the information in the world is linked to a place. For example, the name of the President of the United States, the owner of the house at 110 Main St., and the distance between the hospital and the firestation are all spatial data.

GIS (Geographic Information Systems)

A computerized database management system for the capture, storage, retrieval, analysis, and display of spatial data (Huxhold, Glossary) Strasser (p. 278) describes GIS as having two components: "geographic, describing the location of features, usually in terms of a coordinate system answering the question, 'where is it?'; and attribute or descriptive data, textual answers to the question, 'what is it?'."

GUI (Graphical User Interface)

Allows a user to communicate with a computer's software and hardware through a graphical display (i.e., menus or icons) rather than through a command-line interface (typing commands at a prompt).

IGDS format

Intergraph design format is a non-standard file format that is compatible with only two commercial software packages, MicroStation and InterGraph software. IGDS was the original file format of the MIRIS data.

Land use data

INformation about the utilization of land, i.e.agriculture, industrial property, forest, water, etc.

Map projection

Transfering the properties of a sphere onto a flat plane. This process is only accomplished by some distortion of earth's geographic relationships. There are over 250 different "projections," each distorting the angles, areas, distance, and directions of the earth's surface in a slightly different manner. (Huxhold, Glossary) Certain projections are more accurate than others for displaying differently shaped regions of the earth's surface.

Metadata

Descriptive information about a set of data. Geospatial metadata include the bibliographic and cartographic information of the source map, the current format of the data, and method of obtaining this data.

MIRIS data

(Michigan Resource Information System) Land use data for the state of Michigan organized into township files.

Script

A computer program that automates some function or performs some action. AML scripts make MLDADP functional.

Spatial data (aka geospatial data)

Information that is related to a location. It is estimated that 70% of the information in the world is linked to a place. For example, the name of the President of the United States, the owner of the house at 110 Main St., and the distance between the hospital and the firestation are all spatial data.

Topology

The explicit definition of how map features are related. For example, the statement, "the green house is to the north of the red house, but south of the railroad" defines topology.