Wednesday, January 23, 2013

Critical GIS and the Geoweb 2: Terminology

The following is a non-alphabetised glossary I wrote today for GG3090 class, prompted by a suggestion from a student.  It is an evolving document open to suggestions (the definition of 'map' might be contentious). I'm planning on adding some of these to the New Geoweb Wiki:

GG3090 Glossary
Georeferencing: using known points (such as road intersections) on a geographic information layer (such as a shapefile in GIS) to provide ‘anchors’ to an image with unknown positioning

Database: an information set, usually organised as rows and columns (or fields).  Explicit databases are those that are formalised in a written document or computer file

Map: a graphical representation of a portion of the earth’s surface

Projection: a mathematical procedure or formula for portraying earth-based (i.e. round) data on a flat medium such as a piece of paper or a computer screen

Topology: branch of mathematics concerned with attributes of surfaces that do not change when warped or distorted.  Inclusion, adjacency and connectivity are examples of three such attributes.  Vector layers in GIS require topology specification

Choropleth (map): a map made up of non-overlapping contiguous areas across which a value is evenly distributed as indicated by homogenous colouring of each area

John Snow (map): helped start the field of epidemiology, and an early example of a map ‘mashup’ (see below), John Snow’s map demonstrates the power of visualisation through maps in problem solving.  A distribution of cases of cholera combined with address information led to the identification of contaminated well water as the course of infection (and not air borne causes as previously thought)

Maps of, for and in cyberspace: maps of cyberspace depict material structures of cyberspace itself, usually in the form of numbers and strengths of connections across virtual or real space.  Maps for cyberspace help us understand immaterial aspects of cyberspace in terms of information space and social interaction.  Maps in cyberspace are essentially traditional paper based maps converted into a form (such as a .jpg file) that is uploaded (see the International Encyclopedia of Human Geography)

Ontology: branch of philosophy concerned with existence.  In computer science the term refers to a set of object specifications for use in an application.  A computer map of Cree land contains an ontology of lakes in which parts and certain configurations of lakes have their own categories

Epistemology: branch of philosophy concerned with knowledge and its acquisition

Representation: a mediating factor between an observer and the ‘real’ world.  A map is a representation of the territory it depicts

Mashup: the use of custom datasets on propriety platforms.  A Google Maps mashup takes user-made data and portrays it on a Google Map

Digital divide: a barrier or division, usually socioeconomic in origin, between the haves and the have-nots of digital information access

Geoweb: a set of geographically distributed services

Materiality/immateriality (of cyberspace): materiality includes the physical infrastructures that keep cyberspace ‘going’ such as cables, wires, hardware and bodies.  Immateriality refers to software, information, ideas and social relations that define empowerment or marginalisation in cyberspace

Semiotics: branch of linguistics concerned with sign systems

Map/territory: a mutually constituted set of practices for representing space.  Often the territory is assumed to ‘precede’ the map in the sense that the map represents territory and is therefore an objective portrayal of that territory.  A critical view holds that the map defines territory, producing social relations of human territoriality

Discourse: unspoken rules for producing statements of fact, fiction, science, culture or almost any conceivable aspect of human activity involving sign systems (see semiotics above)

Inscription: a written, recorded, printed, taped, digitally captured or otherwise ‘frozen’ representation of knowledge

Coordinates: a pair of numbers indicating a point (i.e. zero dimensional) location on the surface of the earth

Relational database: a database (see above) in which tables of information connect to each other through the use of primary keys, or columns of identical information found in two or more tables

Relational space: a space defined more by the relations between objects than by the objects themselves

Void space: a space defined more by positions (or coordinates) of objects and their attributes than by  the relations between objects

Wayfinding: travel towards a known goal through the use of landmarks, places and their names

Itinerary: a sequential list of places and distances between them used in wayfinding

Kml: keyhole markup language, the file type used by Google Maps and Earth

Distributed feature: an aspect of landscape that is mappable (i.e. has spatial extent)

Digital earth/virtual globe: an interactive representation of the earth in cyberspace that includes web 2.0 features (see below), as well as aspects of ‘traditional’ maps and atlases (e.g. place names)

Web 2.0: a worldwide web paradigm shift in which the user is able to define the look, feel and content of the resources and structures of cyberspace and the internet

Tracking function (GPS): a global positioning system feature that samples the position of a moving object (i.e. person) at a set rate and links these positions into a line

Waypoints: places encountered and recorded before or during the process of wayfinding

Visualisation: the use of on-screen graphics, maps or other spatial methods to display tabular data

‘Traditional’ GIS: usually refers to anything produced by the Environmental Systems Research Institute (ESRI), the market leader in GIS software over the last few decades

Atomism: a database principle in which information is broken down into its smallest constituent parts

No comments:

Post a Comment