briggidere - 1:21 am on Oct 29, 2010 (gmt 0)

I think that looking at adwords conversion funnels can help see the possible ways they could profile search terms as informational and transactional.

A generic search for a certain brand of bicycle could be considered informational as the user is researching their options, but a search for a particular model of that brand could be seen as more of a transactional search query.

They could even go as far as using that users profile and search history to try to determine the stage of the buying process they are at. Have they already done their research and are ready to buy? Was the research done months ago so they are refreshing their options again so go back to informational rather than transactional even if it's the model of that brand they searched for.
The same query could be both informational and transactional depending on previous user search history