Identification info

Alternative title

Intermediate Geography Centroids 2011

Metadata Language

English

Character set

UTF8

Dataset Reference Date (Publication)

2014-11-06

Dataset Reference Date (Revision)

2021-10-04

Identifier

www.gov.scot / SG_IntermediateZone_Cent_2011

Maintenance and update frequency

Not planned

GEMET - INSPIRE themes, version 1.0

• Statistical units

GEMET - Concepts, version 2.4

• population distribution

• statistical data

IPSV Subjects List

• Statistical analysis

Limitations on Public Access

Other restrictions

Other constraints

No limitations to public access

Use constraints

Other restrictions

Other constraints

Open Government Licence

Other constraints

The following attribution statement must be used to acknowledge the source of the information: Copyright Scottish Government, contains Ordnance Survey data © Crown copyright and database right (insert year)

Other constraints

Dataset is complete for Scotland. Care should be taken when using this dataset with lookups to other postcode based geographies. Some postcode unit boundaries have changed since intermediate zones were created therefore exact match of the boundaries are unlikely.

Spatial representation type

Vector

Denominator

10000

Topic category

• Location
• Society

Code

S92000003

 

Code

EPSG:4258

Code

EPSG:27700

Distribution Information

 

Data quality info

Quality Scope

Dataset

Statement

Centroids for intermediate zone boundaries have been created by the Scottish Government's Geographic Information Science and Analysis Team (GI-SAT) in order to provide a way to link intermediate zones to other (higher level) geographic boundaries used by Scottish Neighbourhood Statistics (SNS) and the wider public sector. Intermediate zone centroids do not represent the geometric centre of the feature, but rather the population weighted centre. For 2001, intermediate zone centroids were calculated as the mean centre of all 2001 data zone centroids contained within an intermediate zone. A detailed methodology for the process used in 2001 can be provided on request.

While the method used to create 2011 Intermediate Zone Centroids remains broadly the same, a small change was implemented following consultation with Local Authorities regarding 2011 Data Zone boundaries. This change was to use the median of locations of data zone centroids contained within an intermediate zone, as opposed to the mean centre. The median is a measure of central tendency and, broadly speaking, the median can be thought of as the 'middle' value. While the mean is calculated by summing all the values together and then dividing by the number of observations, the median is calculated by putting the observations in order, from lowest to highest, and then taking the value in the middle. (Or calculating the mean of the two middle values if there are an even number of observations.). The key advantage of using the median is that it is not as heavily influenced by extreme values as the mean. If an intermediate zone has a highly skewed population distribution, for example a large rural intermediate zone containing a small town in one corner, then the mean can be heavily influenced by the small number of people who live far away from the population centre and the mean will likely fall outside of the town. The median is considered to be a more robust measure of central tendency and is less likely to be influenced by values far away from what would be considered to be the population centre of the intermediate zone.

The process for creating 2011 Intermediate Zone Centroids was automated using ESRI ArcGIS, but the general method is as follows. The median easting and northing coordinate pair for all 2011 Data Zones within the intermediate zone is calculated, giving a notional centroid of the intermediate zone. The distance from each of the data zone centroids to the notional (or median) centroid is calculated using Pythagoras' Theorem. The data zone coordinate pair with the shortest distance to the median was then chosen to represent the centroid of the intermediate zone.

Each 2011 Intermediate Zone has been given a new unique code, following the Scottish Government’s standard naming and coding convention. The Intermediate Zone 2011 codes range from S02001236 to S02002514 (the previous 2001 codes ranged from S02000001 to S02001235). Census 2011 total, resident and household counts have been summed for each intermediate zone and included in the attribute table.

 

Metadata

File identifier

298a25ec-926e-40ca-b74e-60576f8f6dda XML

Metadata Language

English

Resource type

Dataset

Metadata Date

2021-10-05T15:24:46

Metadata standard name

UK GEMINI

Metadata standard version

2.3