Well, this is all rather depressing - I've been seeing comments that Google has been playing around with search functionality again, and not to our benefit! The site: function is really useful - it allows you to limit the results that you get to a specific site such as microsoft.com or a type of site, such as .gov.uk with the search function site:microsoft.com for example. You used to get a listing of all of the pages on a site, and that was useful in a whole variety of ways. Now however, that's changed.
A search for site:microsoft returns a page which lists about 54 million pages, but if you scroll to the bottom of the page, you only have the choice of seeing 30 of them:
However, if you go to the end of the 3 page of results, you'll see this:
If you click to repeat the search, you then get a set of results which gives us the full range, which is what we used to get before. The same thing happens if you add in extra keywords, such as a search for site:microsoft.com library and consequently in order to see a larger set of results I've got to do an extra mouse click for no good purpose. If you try info:microsoft.com and choose to see pages from the site, the same limitation applies. To further compound and confuse this situation, it only seems to happen if you're searching a specific site - a more general search for site:.com library works as it always did.
However, not to worry overly, unless you're running a training course in the next few days, because this is supposed to be a temporary glitch. Google has launched (or if you prefer changed) the domain results functionality. The change means that if you have already seen a series of results from the same domain name, you'll be less likely to see so many in the future. Hopefully this means that you'll now start to get more results from varied sites - and this is a good thing; I've certainly been critical of Google in the past for showing up 6 or 7 results from the same site in the search engine results. Google's Matt Cutts explains the whole domain results thing in more detail in a video over at YouTube.