Richard Alldritt of the UKSA has an excellent blog entry ‘Numbers are Not Enough’ at the RSS’s (beta) StatsUserNet site on the need to have a good grasp of the ‘metadata’ when using official statistics, and even more so, the ‘open data’ that will increasingly be released by central and local authorities.
Dilnot and Blastland have an excellent chapter in Tiger That Isn´t about the way measurement error, gaming, definitions and the whole process of the social construction of data conspire to transform data from what we might think is a transparent representation of the obvious into anything but. They put it extremely well (p. 15; 158):
“we can establish a simple rule. If it has been counted it has been defined, and that will almost always have meant squeezing reality into boxes that don´t fit…The idealised perception of where numbers come from is that someone measures something, the figure is accurate and goes straight in the database. That is about as far from the truth as it is possible to get.”