Beyond the horizon of any sample lies the shadow of the population from which it is drawn. In reality any sample findings immediately beg a number of key questions:

» Is this sample representative of the population e.g. are the characteristics of banks indicated in the sample shared by all UK banks? If not, how is the sample different?

» How can the population be sized on the basis of the sample e.g. how many racks, how much space, how much power does the market require?

The estimates are based on matching Census information on facility profile with corporate profile information also collected. UK corporate turnover has been used as the match variable since the weighting factors from labour force statistics create weighting factors that are too large for statistical validity. However, calculating the size of the UK datacentre market using turnover-based multipliers is too simple and two key factors have been used as correctives in this process:
 

» The size distribution of companies in a sector since one key factor in determining the requirement for datacentre services is organisational size

» The IT dependence of a sector. By definition, sectors and sub-sectors exhibit different levels of reliance on IT ranging from the mission-critical through high, moderate and low dependence to small organisations in the construction and transport sectors where there is lesser use of IT.