Introduction to GIS

Question 1

What is Raster data?

Answer 1

grid of square cells that become points, lines and polygons

Question 2

What is Vector data?

Answer 2

everything is represented using a point, line or polygon

Question 3

What does GIS involve and show?

Answer 3

− Layering is the principle and most important thing

− Shows spatial Relationships between different areas

Question 4

What is Spatial Analysis?

Answer 4

− Analysis of data using its spatial characteristics
− Results are dependent on the locations of the objects being analysed
− Requires access to the locations of objects and their attributes
− May often feed into decision and policy making
− EXAMPLE: John Snow identified clusters of cholera around a water pump in Soho in 1854
− Supported one of the main causes of the disease

Question 5

What is Geographic Data?

Answer 5

− Needs boundaries
− Points, Lines Polygons
− E.g. Census boundaries, Postal Sector

Question 6

What is Attribute Data?

Answer 6

− Numbers e.g. census data

− Want to be able to link it to geographic data

Question 7

Name the 9 Data Issues

Answer 7

−	Date/validity of data – data about data (metadata)
−	Accuracy
−	Scale and generalisation
−	Projections and coordinate systems
−	Modifiable Areal Unit Problem (MAUP) 
−	Ecological fallacy
−	Inconsistency in data and geographies
−	Confidentiality and disclosure risk
−	Purpose

Question 8

Heywood et al., 2006

Answer 8

GIS has been in use since the 1960’s