How Algorithms Work and Relate To Search Engine Optimisation

An algorithm is a set of mathematical equations. The search engines use the algorithm to rank pages to try and show what they deem to be the best results for a particular search.

To explain a little further lets take a good example from the great book by Malcolm Gladwell called Blink.

A must read for anyone interested in psychology and marketing in which he highlights how the Cook County Hospital in Chicago, the inspiration for the hit show ER, used an algorithm to cut down on admissions to its' Emergency Department (ED), saving huge amounts of money and time.

One problem for the build up of patients within this department was down to doctors incorrectly diagnosing symptoms that could lead to a heart attack.

The doctors interpretation of the patients ECG and symptoms often lead to them being admitted to the ED incorrectly putting a huge strain on their resources.

Luckily for them a doctor by the name of Brenden Reilly had recently joined them and upon seeing the problem made it his task to increase the accuracy of diagnosis and in turn reduce the drain on the hospital's resources.

How did he do this? Reilly teamed up with a cardiologist named Lee Goldman. Goldman was at that time involved with a group of mathematicians who were interested in developing statistical rules for telling apart things like subatomic particles.

Goldman used this knowledge to devise an algorithm to streamline the process. Instead of doctors purely relying on patient symptoms, background and ECG results plus a little intuition, the algorithm narrowed it down to 3 key questions plus the ECG which formed a decision tree.

From this a treatment plan was formed thus preventing large numbers of patients being incorrectly admitted to the ED and saving those that slipped through the net and were not admitted.

Eventually after 2 years testing and refining the algorithm, whereby it increased diagnosis accuracy by 70%, it was fully adopted by the hospital.

Now How Does That Relate To The Search Engine Optimisation?

Well on a very basic level, as Google is known to have many many more than just 3 criteria, the search engines filter your page through their own set of mathematical equations or algorithm.

For example if your page title contains 'Red Tank Tops' the search engines will pass your page through their algorithm checking to see if the text on the page contains the same words. If not then your page won't rank in the Search Engine Results Pages (SERPs) for that phrase.

The search engine deems that your page content doesn't relate exactly to that keyword phrase within the title.

This is just one measurement the search engines use but for more tips read my post on basic SEO.

Read further information on Google's algorithm or on how Digg has recently changed it's algorithm that's not impressed some heavy users.