In today’s Google Webmaster Office Hours, John Mueller spent some time talking about quality content and some of the triggers – such as empty listing pages – that are seen as a quality problem.

While talking about quality content, he also said that Google’s quality algos work site-wide, looking at all the indexed content on the entire site and making evaluations on it, and are not on a page by page basis.

From our point of view, our quality algorithms do look at the website overall, so they do look at everything that’s indexed.  And if we see that the bulk of the indexed content is actually lower quality content then we might say ‘well, maybe this site overall is kind of lower quality.

And if you can tell us that this lower quality content shouldn’t be indexed and shouldn’t be taken into account, then we can really focus on the high quality stuff that you are letting us index.

Now, this isn’t exactly news to some SEOs who have long considered the quality algo to be site-wide based on various Googler comments over the years.  However, it is nice to have Google on record as saying that quality algos look at the entire site and not simply on a page-by-page basis – something that was questioned in the Quality Update (aka Phantom 2) earlier this year.

And it is a good recommendation to bump up the overall quality by noindexing the pages that might be dragging the quality down for whatever reason, whether lower quality content or merely empty listing pages, category pages or tag pages.