As pointed out by Jon Husband's comment here in Croeso, blogging is a dialogue process and the blogger learns from others as much as the listeners to the bloggers.
The ideas we are mulling around with is the fact to specially use a blog to learn from key experts (e.g prior to retirement etc), so to that end we need to be able to have some indicators as to whether the blog is useful or not, granted a questionnaire needs to be carefully drafted and maybe a test group set up who have not read the blog but know me, to show their insight on my KM views vs. the insiders of the blog.
But all this is surmountable and I'm not worried this stage about the concrete ness of the results, just indicative.
I guess if we take this idea forward to the next stage (real guinea pigs) we can ask the bloggers opinion of their blogging experience.
One interesting angle on this is we use this technique for real we'd have to do it in our intranet, die to the confidentiality of the subject mater. Question to ourselves is will this stop the blogs from flying (i.e little rss feeds interaction etc, or will it make them fly as we can limit the audience and keep the bloggers knowledge safe to a few?
I think the later will dominate proceedings but we'll see