It’s a fair question to ask. Schema.org metadata is backed by Google, and has the aim of making it easier for people to find the right web pages, so does using it to describe the content of a page improve the ranking of that page in Google search results? The honest answer is “I don’t know”. The exact details of the algorithm used by Google for search result ranking are their secret; some people claim to have elucidated factors beyond the advice given by Google, but I’m not one of them. Besides, the algorithm appears to be ever changing, so what worked last week might not work next week. What I do know is that Google says:
Google doesn’t use markup for ranking purposes at this time—but rich snippets(*) can make your web pages appear more prominently in search results, so you may see an increase in traffic.
*Rich Snippets is Google’s name for the semantic mark up that it uses, be it microformats, microdata (schema.org) or RDFa.
I see no reason to disbelieve Google on this, so the answer to the question above would seem to be “no”. But how then does using schema.org make it easier for people to find the right web pages? (and let’s assume for now that yours are the right pages). Well, that’s what the second part of the what Google says is about: making pages appear more prominently in search result pages. As far as I can see this can happen in two ways. Try doing a search on Google for potato salad. Chances are you’ll see something a bit like this
You see how some of the results are embellished with things like star ratings, or information like cooking time and number of calories–that’s the use of rich snippets to make a page appear more prominent.
But there’s more: the check boxes on the side allow the search results to be refined by facets such as ingredients, cooking time and calorie content. If a searcher uses those check boxes to narrow down their search, then only pages which have the relevant information marked-up using schema.org microdata (or other rich snippet mark-up) will appear in the search results.
So, while it’s a fair question to ask, the question posed here is the wrong question. It would be better to ask “will schema.org metadata help people find my pages using Google”, to which the answer is yes if Google decides to use that mark up to enhance search result pages and/or provide additional search options.
I have been involved in the LRMI (Learning Resource Metadata Initiative), which has proposed extensions to schema.org for describing the educational characteristics of resources–see this post I did for Creative Commons UK for further details. I have promised a more technical briefing of the hows and whys of LRMI/Schema.org to be developed here, but given my speed of writing I wouldn’t hold my breath waiting for it.–In the meantime this is one of several questions I thought might be worth answering. If you can think of any, let me know.