Description: This file contains the digital vector boundaries for Middle Layer Super Output Areas as at December 2011 in England and Wales. The 2001 Output Areas and Super Output Areas were maintained using 2011 Census data, and are referred to as 2011 Output Areas and Super Output Areas. Super Output Areas (SOAs) are a geographic hierarchy designed to improve the reporting of small area statistics. In consultation with local authorities, the 7,201 Middle Layer SOAs in England (6,791) and Wales (410) were built from groups of Lower Layer SOAs and are constrained by the 2011 local authority boundaries. They have a minimum of 5,000 residential population (an average of 7,700) and 2,000 households (an average of 3,200). Please note though that E02006781 (Isles of Scilly 001) is much smaller than this, but has been included as a pseudo-MSOA to give complete national coverage. The majority of Middle Layer SOAs have not changed since 2004, allowing time-series comparison of statistics at that level. Users should be aware of this when using MSOAs for statistical presentation. The boundaries are Intermediate/Generalised (20m). Intermediate datasets are designed for high quality mapping, preserving much of the original detail from the full dataset, but typically 10% of the file size. They are great when used in conjunction with the OS raster products and for producing detailed regional and local maps, or large wall maps. They are also suitable for non-demanding GIS analyses (such as buffering). Intermediate datasets are a good compromise between detail and small file size. They have also been clipped to the clipped to the coastline (Mean High Water mark), giving the coastline a more orthodox appearance. Please note that this product contains both Ordnance Survey and ONS Intellectual Property Rights.