While each SOA is of higher resolution than the highest resolution "ward" index data of the IMD2000 and therefore better at identifying "pockets" of deprivation within wards the 2004 system has its problems. Some areas of deprivation can still be hidden because of the size of SOAs. Examples of this can be found by comparing central areas of Keighley using the Bradford District Deprivation Index (a Deprivation index developed by Bradford Council produced at 1991 Census Enumeration District level) with the ID2004.