academic research: New learning created
by the activity of university and other scholars.
ad hoc: For the particular case at
adjacency: The topological property
of sharing a common boundary or being in immediate proximity.
analysis: The stage in science when
measurements are sorted, tested, and examined visually for patterns and predictability.
arc/node: Early name for the vector
GIS data structure.
arc: A line represented as a set of
area feature: A geographic feature
recorded on a map as a sequence of locations or lines that taken together
trace out an enclosed area or ring that represents the feature. Example: a
attribute: A characteristic of a feature
that contains a measurement or value for the feature. Attributes can be labels,
categories, or numbers; they can be dates, standardized values, or field or
other measurements. An item for which data are collected and organized. A
column in a table or data file.
AUTOCARTO (International Symposium on Automated
Cartography): A sequence of computer cartography and GIS conferences.
cartography: The science, art, and
technology of making, using, and studying maps.
CGIS (Canadian Geographic Information System):
An early national land inventory system in Canada that evolved into a full
choropleth map: A map that shows numerical
data (but not simply "counts") for a group of regions by (1) grouping
the data into classes and (2) shading each class on the map.
computer mapping: Producing maps using
the computer as the primary or only tool.
connectivity: The topological property
of sharing a common link, such as a line connecting two points in a network.
context-sensitive help: A component
of a user interface that can reveal to the user information that assists with
the current status of other elements of the user interface.
data structure: The logical and physical
means by which a map feature or an attribute is digitally encoded.
database: The body of data that can
be used in a database management system. A GIS has both a map and an attribute
database manager: A computer program
or set of programs that allows a user to define the structure and organization
of a database, to enter and maintain records in the database, to perform sorting,
data reorganization, and searching, and to generate useful products such as
reports and graphs.
digitizing tablet: A device for geocoding
by semi-automated digitizing. A digitizing tablet looks like a drafting table
but is sensitized so that as a map is traced with a cursor on the tablet,
the locations are picked up, converted to numbers, and sent to the computer.
Duekers definition (of GIS): "A
special case of information systems where the database consists of observations
on spatially distributed features, activities or events, which are definable
in space as points, lines, or areas. A geographic information system manipulates
data about these points, lines, and areas to retrieve data for ad hoc queries
FAQ: A list of frequently asked questions,
usually posted on a network newsgroup or conference group to save new users
the trouble of asking old questions over again.
feature: A single entity that composes
part of a landscape.
file: Data logically stored together
at one location on the storage mechanism of a computer.
format: The specific organization of
a digital record.
FORTRAN: An early computer programming
language, initially for converting mathematical formulas into computer instructions.
fourth dimension: A common way of referring
to time; the first three dimensions determine location in space, the fourth
dimension determines creation, duration, and destruction in time.
functional definition: Definition of
a system by what it does rather than what it is.
g-trade: (also g-commerce): Web-oriented
use of GIS capability to spatially enable the search and browse processes
during online business activity or e-trade.
GBF (Geographic Base File): A database
of DIME records.
general-purpose map: A map designed
primarily for reference and navigation use.
geocoding: The conversion of analog
maps into computer-readable form. The two usual methods of geocoding are scanning
geographic information science: Research
on the generic issues that surround the use of GIS technology, impede its
implementation, or emerge from an understanding of its capabilities.
geographic(al) information system: (1)
A set of computer tools for analyzing spatial data; (2) A special case of
an information system designed for spatial data; (3) An approach to the scientific
analysis and use of spatial data; (4) A multibillion- dollar industry and
geographic pattern: A spatial distribution
explainable as a repetitive distribution.
geography: The science concerned with
all aspects of the earths surface, including natural and human divisions,
the distribution and differentiation of regions, and the role of humankind
in changing the face of the earth.
GIS/LIS: A U.S. national conference
on geographic information and land information systems, sponsored by most
GIS professional organizations and held annually.
GUI (graphical user interface): The
set of visual and mechanical tools (such as window, icons, menus, and toolbars,
plus a pointing device such as a mouse) through which a user interacts with
information: The part of a message
placed there by a sender and not known by the receiver.
information system: A system designed
to allow the user to be delivered the answer to a query from a database.
installed base: The number of existing
Internet: A network of many computer
networks. Any computer connected to the Internet can access any of the computers
accessible through the network.
isoline map: A map containing continuous
lines joining all points of identical value.
killer app: A computer program or "application"
that by providing a superior method for accomplishing a task in a new way
becomes indispensable to computer users. Examples are word processors and
land-cover map: A map showing the type
of actual surface covering at a given time. Categories could be grassland,
forest land, cropland, bare rock, and so on.
land-use map: A map showing the human
use to which land is put at a given time. Categories could be pasture, national
forestland, agricultural land, wasteland, and so on.
landscape: The part of geographic space
showable on a map, including all its features.
learning curve: The relationship between
learning and time. A steep learning curve means that much is learned quickly
(usually thought to be the opposite). A difficult learning curve is one where
learning takes place slowly, over a long period.
line feature: A geographic feature
recorded on a map as a sequence of locations tracing out a line. An example
is a stream.
LIS (Land Information System): Surveying
professions term for GIS where that data are for land ownership.
location: A position on the earths
surface or in geographic space definable by coordinates or some other referencing
system, such as a street address or space indexing system.
LUNR (Land Use and Natural Resources Inventory
System): An early GIS in New York.
map: A depiction of all or part of
the earth or other geographic phenomenon as a set of symbols and at a scale
whose representative fraction is less than 1:1. A digital map has had the
symbols geocoded and stored as a data structure within the map database.
map overlay: Placing multiple thematic
maps in precise registration, with the same scale, projections, and extent,
so that a compound view is possible.
measurement: A quantitative assessment
of a phenomenon.
menu: A component of a user interface
that allows the user to make selections and choices from a preset list.
MIMO system: A term used to describe
a first-generation computer mapping system designed to capture the map by
computer and reproduce it (map inmap out).
MLMIS (Minnesota Land Management System):
An early statewide GIS for Minnesota.
modeling: The stage in science when
a phenomenon under test is sufficiently understood that an abstract system
can be built to simulate the real system.
modular computer program: Computer
programs composed of integrated sections of reusable functions rather than
a single program.
National GIS Curriculum: An NCGIA-sponsored
national college curriculum for GIS, used in many colleges and universities
worldwide and with available teaching materials.
National Spatial Data Clearinghouse: A
World Wide Web resource that serves as a cross- reference point for the distributed
database of all U. S. government public-domain and other geographic information.
NCGIA (National Science Foundations National
Center for Geographic Information and Analysis): A three-university consortium
funded to assist in GIS education, research, outreach, and information generation.
newsgroup: An area on the Internet
for asynchronous many-to-many discussions.
node: At first, any significant point
in a map data structure. Later, only those points with topological significance,
such as the ends of lines.
observation: The process of recording
an objective measurement.
Odyssey: A first generation GIS developed
at Harvard to implement the original arc/ node vector data structure.
on-line manual: A digital version of
a computer application manual available for searching and examination as required.
overlay weighting: Any system for map
overlay in which the separate thematic map layers are assigned unequal importance.
PC (Personal Computer): A self-contained
microcomputer, providing the necessary components for computing, including
hardware, software, and a user interface.
point feature: A geographic feature
recorded on a map as a location. Example: a single house.
prediction: The scientific ability
to forecast the outcome of a process in advance.
proceedings: The formal record of the
papers and other prepared presentations at a conference. Usually available
to conference attendees then distributed as a soft-cover book.
professional publication: Books, journals,
or other information designed primarily for those using GIS technology as
part of their job.
query: A question, especially if asked
of a database by the user via a database management system or GIS.
record: A set of values for all attributes
in a database. Equivalent to a row in a data table.
scientific approach: A method for rationally
explaining observations about the natural and human world.
search engine: A software tool designed to
search the Internet and the WWW for documents meeting the users query. Examples:
Yahoo and Alta Vista.
software package: A computer program
spatial data: Data that can be linked
to locations in geographic space, usually via features on a map.
spatial distribution: The locations
of features or measurements observed in geographic space.
spreadsheet: A computer program that
allows the user to enter numbers and text into a table with rows and columns
and then maintain and manipulate those numbers using the table structure.
thematic map: A map designed primarily
to show a "theme," a single spatial distribution or pattern, using
a specific map type.
topographic map: A map type showing
a limited set of features but including at the minimum information about elevations
or landforms. Example: contour maps. Topographic maps are common for navigation
and for use as reference maps.
topology: The numerical description
of the relationships between geographic features, as encoded by adjacency,
linkage, inclusion, or proximity. Thus a point can be inside a region, a line
can connect to others, and a region can have neighbors.
transparent overlay: An analog method
for map overlay, where maps are traced or photographed onto transparent paper
or film and then overlain mechanically.
U.S. Census Bureau: A part of the Department
of Commerce that provides maps in support of the decennial (every 10 years)
census of the United States, especially the census of population.
user group: Any formal or informal
organization of users of a system that share experiences, information, news,
or help among themselves.
USGS (U. S. Geological Survey): A part
of the Department of the Interior and a major provider of digital map data
for the United States.
vector: A map data structure using
the point or node and the connecting segment as the basic building block for
representing geographic features.
workstation: A computing device that
includes as a minimum a microprocessor, input and output devices, a display,
and hardware and software for connecting to a network. Workstations are designed
to be used together on local area networks, and to share data, software, and
World Data Bank: One of the first digital
maps of the world, published in two versions by the Central Intelligence Agency
in the 1960s.
World Wide Web (WWW or W3): A distributed
database of information stored on servers connected by the Internet.