econman - 9:51 pm on Jun 20, 2006 (gmt 0)

I think the words "Authority" and "Quality" refer to somewhat different phenomena, but there is some overlap, and these phenomena tend to be closely correlated in actual practice, so we tend to confuse them.

Unlike some others, I don't think these concepts are entirely subjective or incapable of being detected on the basis of quantitative evidence.

The key attributes that make a site an "authority" on a specific topic:

1.The site offers a lot of information about the topic.
2.The information tends to be very accurate.
3.The site has been (or eventually will be -- if it is relatively new) recognized by both users and by experts in the field as an authoritative source of information on that particular topic.

Some key attributes of site "quality"

1.The information is accurate, and drawn from reliable sources, or is based on the author's own expertise.
2.The information is well organized and easy to find.
3.At least some of the information is uniquely available from this source – they've gone to the effort, or care so deeply about their topic that they have deeper, more comprehensive information than other sites.
4.The site is aesthetically pleasing – no annoying ads screaming in your face.
5. If you look closely, you discover that the site has been skillfully prepared by people who care about their craft – the words are well written, the photos are sharp and well composed, the graphic design is both visually pleasing and effective, the site architecture is sound, it is W3C compliant, etc.

The other key point is that a high quality site may have a document that is relevant to a particular query, but the site may not have many other documents that are on point, and in general it may lack sufficient in-depth information about the topic to justify placement high in the SERPs for that query.

For instance, a major university site might display uniformly high quality, and it might be the ultimate authority on the course offerings and professors at that particular school; but it may or may not contain detailed, useful information about any specific academic topic.

Even if the university has several Nobel Laureates in Physics on their faculty, that doesn't mean the school's web site is necessarily an authority on Physics, or any specific topic within that niche.

Someone searching for information about Quantum Mechanics would not be well-served by a search engine that takes them to a page with the current semester's schedule of courses in Quantum Mechanics, even if that page happens to use the words "Quantum Mechanics" and "Physics" in the URL.

The key to solving this puzzle is – at least in part – looking past individual documents, and individual words, to consider how many other words, and how many other documents are included on that site that are directly related to that particular topic, as well as closely related topics.

You have to look for entire clusters of documents, and clusters of specific, related words within those documents, in order to identify and define each "niche".

You should strive to not only identify "quality" sites but also strive to find documents that sit within a cluster of closely related documents.

To solve the problem people have been complaining about, you need to be displaying more documents in the top 30 portion of your SERPs that are taken from the relatively small group of high quality sites that has the most in-depth coverage of that particular topic.

Just to be safe, be sure to throw in some documents from Wikipedia, or Encarta, the BBC, that site "about" stuff, sites like Expedia, etc. and you'll probably have pleased the user. But you can't just show documents from those mile wide and inch deep sites; if that's all you do, you aren't really helping users and you'll continue to get a lot of complaints from folks struggling to build and maintain "authority" sites within narrow niches (an important subset of the folks who hang out at WebmasterWorld, along with the spammers, SEO experts, etc.)

One last thought.

One of the things many of us love about MSN is that it hasn't relied on "sandbox" features that tend to make it nearly impossible for new sites to appear in the SERPs.

In that regard, don't overreact to the "authority" concept, but waiting until a site has been around long enough to be widely recognized as an "authority" site.

If a high quality site has enough information on a particular topic, and it been around a long time, chances are it is already recognized as an "authority";.

But, if a site is relatively new, or the niche it serves is very obscure, the site may not yet be widely known, and thus it may not yet have been recognized as an "authority".

If you can find those sites, and give them some visibility, you will serve your users well, and you will help these sites become better known, so that eventually even the big "G" will grant them "authority" status.

(Or, you could think of one of these newer in-depth sites as being a nascent "authority" which hasn't yet been recognized as such).