Usually the purpose is to chart the changes in the intervening 12 months in perceptions of the companies.
The normal interview tactic is to ask questions about a whole list of companies so the interviewee does not know who the sponsor is. For any journalist who is moderately alert, this secret lasts about five minutes. It becomes obvious who is paying because if you say anything out of the ordinary, it opens the gate for a series of follow-up questions, but only if the comment concerns a sponsor. So if you give the maximum negative score as a first answer to every company listed, then those companies mentioned in the follow-up questions are the ones footing the bill.
If you are then completely cynical and want to get the interview over with as quickly as possible, all you have to do thereafter is say nothing controversial - give the sponsors an 'about average' for everything.
What was interesting this year was a subtle change of emphasis in the questions dealing with in-house PR teams, and the criteria by which they should be judged. Traditionally, these questions have been along the lines of whether one trusts them as a primary source of information and at what point the journalist needs to switch to someone further up the corporate hierarchy, coupled with a pecking order emphasis of which company the journalist would phone for information.
This year the emphasis was quite different. Traditionally all the questions have been reactive - how the PR department does or should handle a journalist's requests. This time there was much more emphasis on the proactive - the role of the PR department in taking the initiative to produce stories.
This seems to me a very significant shift. The media call the shots less and less. Well-resourced PR departments have a huge if unseen influence on the news agenda. How long before these surveys instead ask PROs which journalists they bother to approach?