Statistics, statistics

If you’ve Googled today, you may have noticed that the Google search page no longer says it indexes over eight billion web pages. An article, ‘Google: Our search is bigger than your search‘, in Silicon.com, says Google has stopped boasting about the size of its index "because people don’t necessarily agree on how to count it".

This strikes a familiar chord with me, as I have regularly had debates with other UK providers in the construction collaboration technology market about the size of their user base, number of projects, etc. From its earliest days, BIW, for example, made no secret of how many users, from how many companies, working on how many projects, it had using its application. It publishes these details on its home page, and regularly updates its other metrics via news releases. Most other providers, however, are more reticent. Some publish no figures at all. Others, notably Cadweb, publish numbers that are clearly based on a different way of counting.

Today, Cadweb’s statistics show it hosts just under four million items associated with 175 projects – an average of 22,839 items per project. Of the total number of items, some 2.1 million are drawings – meaning that there were around 11,780 drawings per project. Of course, this sounds very impressive, but to anyone with a working knowledge of the construction process the numbers are way too large. Presumably, Cadweb’s drawing total relates mainly to the total number of drawing copies and/or revisions. For example, if a single drawing is issued to, say, ten people, Cadweb presumably records that as 11, one original plus 10 electronic ‘copies’.

BIW, by comparison, is more up-front about its statistical policies. It counts its drawings once only; and, in a November 2004 news release, it said drawings on its 2300-odd projects were issued, on average, to an eight-strong issue list. The one million drawings it had at that date, would therefore have been augmented by a further eight million electronic ‘copies’. The number of original drawings per BIW project is – to my mind – much more realistic (around 460); the ‘copies’ would increase the total circulated to around 4140, while any drawing revisions would increase the number still further. I suspect, though, the final figure will still be well under that suggested by Cadweb’s project statistics.

If we are to make meaningful comparisons in the capabilities and capacities of different providers’ systems (and their infrastructures), there is clearly a need for an agreed way of counting drawings and documents, plus the host of electronically generated items (ranging from transmittals to instructions, requests for information (RFIs), change orders, etc). In my view, it makes sense to count all the items once only, regardless of the number of individuals on an issue list; allowances might also have to be made for drawing revisions. But I dare say Cadweb wouldn’t agree as its numbers might appear less significant.