Open Data is great (what is it again?) | Dan Hughes | Pulse | LinkedIn

"1. Open data

Open data can be split into two further sub-groups.

1a. By-product - Data that is produced as a means to an end. Transport times seems to be the most widely used example. No train company is set up with the objective to produce timetables, but without them, running a service is somewhat tricky. This being made available has (relatively) little cost and is in the interest of everyone.

1b. Product - There are a number of data sets that are produced where the whole point is the data… the data itself is the product. The MET office or Ordnance Survey for example in the UK, is set up to produce data sets. This has a significant cost and is normally used by a relatively small sub-groups of users. Making this data open means someone needs to cover the costs (assuming that it is agreed that it is needed at all). For these sorts of public sector data sets to be open, they need to be funded by central government. (The alternative approach is that as only the people getting the benefit from it should pay rather than everyone. This point seems to be the source of much of the discussions about open data and is the difference between being open or shared.)"