This post stems from a GoogleWebmasterHelp video on how Google search results are created that was posted by Matt Cutts in April 2012. If you don’t subscribe to this YouTube channel and you have an interest in what Google does then it’s certainly worth a look. At the time of writing the video is already nearly 18 months old and so doesn’t include the latest updates but it still gives a pretty good overview of how a Google search works.
So how does Google do what it does?
There are three things that Google, or indeed any other search engine, needs to do well if it wants to be useful to people.
- Crawl the web comprehensively
- Effectively index the pages
- Apply a ranking to the pages depending on a range of quality criteria
Crawling the Web
When Google started it would take it some months to crawl the entire Internet at a time when the World Wide Web was a much smaller place than it is today. This could mean that quite a long time would go by before any changes on your website would be noticed and incorporated into search results. Happily things happen much more quickly today and many of us expect that changes made to our site today will show up tomorrow or the day after in the search results. The prime determinant of how frequently Google re-indexes your site is Page Rank, with high Page Rank sites being indexed far more frequently than those with low Page Rank.
Page Rank is a metric of which most web users are blissfully unaware but to those who make a living from SEO it is an extremely important factor. Whatever browser you are using there will likely be a plug-in which will allow you to access the page rank of the site you’re currently inspecting and I would certainly advise you to take a look.
Google ranks pages from 0 to 10 where 0 implies the lowest rank and numbers approaching 10 are reserved for very high prestige sites with many visitors. Academic websites usually have a high page rank as do high-quality news sites like the BBC or CNN etc. Google uses page rank as an indication of how high quality a site is, as well as how many visitors it has and how frequently updates are made.
The primary determinant of Page Rank is how many links come into a site but crucially it also depends on the Page Rank of those linking sites themselves. This begins to explain how crucial it is to have links into your site from high quality domains; and equally how problematic it can be to have a lot of very low quality links. If we go back a couple of years, Google search results were strongly influenced by the number of links and far less by their quality. Although it contravened Google’s own advice, many Webmasters got excellent results by simply buying large numbers of links from sites, often called ‘link farms’, that were set up solely for the purpose of providing links to websites that paid for the privilege.
However, incremental updates to Google’s search software over the last few years has changed this balance, with the quality of your incoming links becoming significantly more important. These updates mean that today, Google takes an increasingly dim view of this ‘link farming’ and will penalise a site for having too many links from very low quality websites. Even high quality websites which would have previously ranked well are suddenly finding themselves well down search results with their Webmasters desperately trying to remove low quality links into their site they set up a few years ago. This can be significantly more difficult than it sounds and whilst backlinks are a crucial determinant of your Page Rank, you should be very wary of who you invite to make a link to your website.
I cannot express strongly enough that other than ensuring that your site has high-quality original content and your on-page SEO is done properly, by far the most important thing you can do to improve search ranking is to get links into your site from other high-quality websites.
Page Indexing and Ranking
After it has crawled the web, Google must construct an index so that it can get an idea of what each page is actually about. When the Googlebot crawls a site it can identify text and in many cases it can read downloads such as PDF’s etc. The only way it can identify what’s in a diagram is if you’ve added ‘alt’ text so if this isn’t something you routinely do you’re missing a trick. This is also the reason why you should avoid having text on your site that’s actually part of a graphic as Google will not be able to read it.
Google looks at the elements on your page that it can understand and will fit them into its index of likely keywords. Google will essentially ignore words commonly used in language and will focus on words it believes are significant in highlighting the subject of the page. It will also look at links into your site which use the relevant keywords in their anchor text highlighting the importance of properly forming link text. Although quite a clever beast, the Googlebot is simply software and the easier you can make it to understand what your page is about then the better for all concerned.
Google Search Results
When you enter a search phrase, Google will look at its index of pages which include these keywords. If some pages from your site include multiple keywords from the search phrase then it will give your site preference, especially if the words are in the same order as the search phrase. It will then decide which pages to serve up in the Google search results depending on how well your search phrase has been matched together with the Page Rank of the matching sites. The results page should be in the order of similarity with the keyword phrase with the higher page rank sites showing first.
It’s clear that to be successful in searches your webpages must be well written with the keywords appearing sufficiently frequently to get Google’s attention. At the same time the page should look authoritative having both back and forward links to and from quality sites. If a keyword appears too frequently then the search software will take the view that the article has been ‘keyword stuffed’ and is likely to be of low quality. How frequently is too frequently? The page should read correctly. If the keyword appears with sufficient frequency that that it interrupts the flow of normal English then Google is likely to take note and give you a lower quality score (which highlights the importance of considering your keyword or phrase very carefully). But if your page has enough of the right words and you have sufficient Page Rank then you’re always going to be close to the top of the Google search results.
Contact Colin Fenwick for more information or if you would like to talk to Web Incite about how we can help you to improve your website’s performance.