Measurement and Spatial Data - Part 1 Flashcards
Explain the trend:
Demand for geographic information has outstripped supply
Historically, demand for geographic information has outstripped supply.
The need and desire to catalog and present geographic information continues to grow.
As technology becomes more available and user friendly, culturally, GIS has become more and more integrated into our daily lives.
Why is GIS integral to problem solving?
Many problems have are geographic in nature, context or consequence.
Classifying Geographic Problems
Scale
Purpose
Time-Scale
Geographic problems and SCALE
Essential in defining a problem
Geographic problems and PURPOSE
often problems or their solutions have a specific purpose, and that purpose is geographic
Geographic problems and TIME-SCALE
Often problems have a specific time-scale.
The scale may vary, and/or may include updated information.
MAP
- A map is a representation of what is usually some portion of Earth’s surface as seen from above at a greatly reduced size.
- A set of symbols recorded in spatial relationship to each other.
Symbols (maps)
Symbol position is integral to the message being delivered.
Map Reader role
Interprets the relationships between the symbols, deciphering geographic information.
Reading the map’s message, the reader is able to perform/understand spatial operations.
Maps control our
Maps control our perception of geographic information.
Information Systems help us… how?
They help us manage what we know, making it easier to:
ORGANIZE
STORE AND ACCESS
RETRIEVE, MANIPULATE and ANALYZE
Data, Information and Knowledge.
Information Systems help us to manage what we know, making it easier to organize, store and access, retrieve, manipulate and analyze…..
DATA
INFORMATION
KNOWLEDGE
DATA
Most mundane form of information (text, symbols, numers), assembled into a database.
The raw material for information.
INFORMATION
Essentially: data with meaning. Data that has undergone processing/analysis to make it meaningful in regards to the given topic of interest.
KNOWLEDGE
Information being interpreted and understood.
Dependent upon the readers’ experience, expertise and needs.
TYPES OF KNOWLEDGE
CODIFIED
TACIT
CODIFIED knowledge
written and transferred with ease.
TACIT knowledge
slow to acquire and difficult to transfer.
KNOWLEDGE VS. INFORMATION (3)
Knowledge:
- Entails a “knower”/people.
Information exists independently. - Is harder to detach from the “knower” than information. Transferring it between people is more difficult than information.
- Requires assimilation. We digest it, rather than hold it. We may hold conflicting information, but seldom hold conflicting knowledge.
SPATIAL DATA
Data that has unique geographic coordinates or spatial identifiers that allow the data to be located in geographic space.
(not limited to Earth’s surface!)
Spatial data has
- a known location
- can have attributed aspatial data attached
Time (its role in a GIS context)
Always plays an implicit role.
GEOGRAPHIC INFORMATION SYSTEMS (def 1)
A system of hardware, software, data, people, organization and institutional arrangements for collecting, storing, analyzing, and disseminating information about areas of the earth.
GIS definition (broken down 6,4)
A system of:
HARDWARE
SOFTWARE
DATA
PEOPLE
ORGANIZATION
INSTITUTIONAL ARRANGEMENTS
.... for :
COLLECTING
STORING
ANALYZING
DISSEMINATING
GEOGRAPHIC INFORMATION SYSTEMS (def 2)
A system designed to capture, store, manipulate, analyze, manage and present all types of spatial or geographical data.
Information System
Integrated set of components working together to collect, process, store, and disseminate information to support decision making, coordination, control, analysis, and visualization in an organization.
How is GIS different from other information systems?
Much of the information is spatial and can be analyzed using special spatial analysis algorithms.
Tools are created with..
Cultural, social and historical context to serve changing needs, tools and also chang their environment.
People use GIS to (4)…..
MEASURE
REPRESENT
OPERATE
TRANSFORM
People use GIS to MEASURE….
aspects of geographic phenomena and process
People use GIS to REPRESENT….
measurements, usually in the form of a computer database, to emphasize spatial themes, entities and relationships.
People use GIS to OPERATE….
upon representations to produce more measurements and to discovr new relationships by integrating disparate sources
People use GIS to TRANSFORM
these representations to conform to other frameworks of entities and relationships.
Representationalism
Refers to the notion that measurement is a connection of numbers with entities that are not numbers.
Stevens (1946) of Harvard proposes a framework… which framework is this?
Levels of Measurement
Levels of Measurement (defined by egan)
A group of measurement scales based on the invariance of certain properties.
