1. 1 Quality Assessment in grid statistics Data quality and coverage ESTP course on Geographic Information Systems (GIS): Use of GIS for making statistics in a production environment Statistics Norway, Oslo, 26th to 30th of March 2012 Attribution (by) Licensees may copy, distribute, display and perform the work and make derivative works based on it only if they give the author or licensor the credits in the manner specified by these. http://creativecommons.org/licenses/by/3.0/ Mr Vilni Verner Holst Bloch MSc Resourcs Geography and Landscape Ecology Statistics Norway 460 Construction and service statistics Oterveien 23 N-2225 Kongsvinger NORWAY vvh@ssb.no Tel: +47 6288 5097 Mob. +47 9482 2532

2. 2 Standard for Quality Reports To be interpreted into GIS terms - geographical accuracy - geographical coverage - georeferencing methods …

3. 3 Population and Housholds unit IT Archive unit Housing and Buildings unit Population and housing example

4. 4 Statistics Dwelling statistics Housing census Constructions Builfing stock Levekårundersøkelser Sources Properties register Population register Dwelling surveys Dwelling sales ingormation Ownership register Census 2001 Actual addresses Elevator register Tax information Water supply maps Sewage maps … Lots of variables, sources and statistics attached to dwellings

5. 5 Principles Use best sources : - use authorative sources first (e.g. …) - use newest information (e.g. new dwelling sales before old…) - imputation if enhancing statistics (coverage, detail level, bias etc…)

6. 6 Persons without dwelling Inhabited dwellings vacant dwellings new dwellings Micro file ID N - 1 (often N – N, sometimes 1 - 0) Published variablesNew variables AB C persons dwellings

7. 7 Percentage unknown 200620072008200920102011 Urban/rural1,060,130,080,040,050,11 Building year 9,129,469,219,028,42 Number of rooms 11,4911,2611,6711,6611,54 Utility floor space 7,677,106,595,845,33 Number of baths 11,0610,8511,1911,0510,88 Number of WC 10,9810,7811,1210,9510,79 Number of floors in building 0,500,08 Kitchen 0,880,93 Floor entrance 0,140,16

8. 8 08455: Dwellings, by number of floors in the building (M) municipality unknown Kristiansand4757 Oslo656 Surnadal446 Steinkjer348 Drammen193 Bardu128 Tønsberg124 Sandefjord120 Sandnes109 Halden104 municipalityUnknown Oslo336 Åsnes105 Volda100 Grue89 Flora88 Frøya69 Gaular67 Øystre Slidre56 Fauske55 Hitra53 08457: Dwellings, by position (floor) in the building (M) Quality in dwelling statistics (municipalities)

9. 9 Water supply points from digital maps Example water supply Dwellings and distance to water supply

10. 10 Dwellings on grids Dwellings per 5x5 km grid cell http://www.ssb.no/emner/01/01/20/tettstedkart/main.html Oslofjord area Southern Norway mountains

11. 11 Dwellings on grids http://www.ssb.no/emner/01/01/20/tettstedkart/main.html Region Oslo Region Kongsvinger Dwellings per 5x5 km grid cell

12. 12 Dwellings on grids Dwellings per 250x250m http://www.ssb.no/emner/01/01/20/tettstedkart/main.html

13. 13 Quality in dwelling statistics on grid 2010 MissingOn gridStatisticsDifference % VarTitle (EN)2010 dwe_todwDwellings in all23 9232 300 0022 323 9251,03 dwe_detDwellings in detached houses12 1831 207 7201 219 9031,00 dwe_2dwDwellings in tomannsboliger2 911208 685211 5961,38 dwe_rowDwellings in rekkehus, kjedehus og andre småhus2 944264 877267 8211,10 dwe_multDwellings in boligblokk4 282518 710522 9920,82 dwe_comDwellings in bofellesskap47140 72441 1951,14 dwe_othDwellings in andre bygningstyper1 13259 28660 4181,87 dwe_aveaAverage utility floor space109123 Missing or incorrect coordinates. Norway.

14. 14 Dwellings with no information on utility floor space Dwellings in all Quality in dwelling statistics on grid Coverage for utility floor space. Whole country: 92,9 % 1x1 km grid cells in Trondheim area 60% 85%

15. 15 2008 - 2012 Change (N buildings)N (5x5 km) + 1 - 94 27934,3 + 10 - 992 49620,0 + 100 og mer3632,9 No change3 63829,1 Decrease1 70712 48313,7 No buildings8 264

16. 16 Buildings. Shares per 5x5 km 2 and year. 2007-2012. Inspection of changes. Changes in coordinates due to wash of registers or real changes?

17. 17 Buildings. Change 2007 – 2012. 5x5 km 2 Net more buildings Net fewer buildings Net more (red) and fewer (blue) buildings

18. 18 Buildings. Change 2007 – 2012. 5x5 km 2 Real changes or due to different administrative routines?