In our post about how Google works we showed you a video created by Google which explained some of the basic mechanics behind the website we all turn to when looking for things on the web. In reality modern search engines are far more complex than anyone could sum up in a 3 minute video and one area that is not covered is personalisation.
In the video Googles Matt Cutts explains that to work out which pages a user really wants Google asks questions, over 200 of them. Most of the questions Google will ask will be focused on the potential pages that could appear in your search result, a few of the questions will relate to the person doing the searching.
On a very basic level, the aim of a search engine is to provide the best list of web results that relate to a search query entered by a user. The thing is that users are people and people are different, good search results for me may not be so useful to you. Search engines realise this and to ensure they provide the best results possible they will try to personalise your search results.
A common example of this would be if you were searching for a restaurant, there is a good chance that good search results for me would be useless to someone living on the other side of the planet. To solve this issue Google can work out my approximate location via my IP address and give me results for restaurants in my area and do the same for anyone else. We all get the most relevant results for us.
Search results being personalised by location is a great example of what we are talking about but personalisation can extend much deeper than that. Search engines could use all sorts of information to personalise your search results such as your search history and browsing history.
The main issue with personalisation is that while a search engine like Google may be able to look at the historical search habits used on a specific PC, plenty of people share a PC (like those with a family computer) or use more than one PC on a regular basis (you may have a work computer and a home Computer). For this reason, while my Google search results may not be exactly the same as your Google search results, on the whole they will be very similar except for location based results.
You may have noticed that Google is a very generous company that provides a huge range of tools and resources to everyone free of charge:
all you have to do is sign up for a Google account... And there is the missing link.
By signing into a Google account you enable Google to take all that information and link it to a person, you. What's more Google can use all these products to gather additional information about you. A great example of this is Google+ their social media platform.
Below are two search results from Google for the word "entities", a very vague term that could be to do with a wide range of subjects. The left results were when I was not signed into Google and the while the results on the right were displayed when I was signed in:
The result I have highlighted was shared by a website I follow on Google+ and read on a regular basis called Search News Central. Because I signed into Google it knew it was me searching, irrespective of what PC I was on and it also knew I followed Search News Central. Google realised that there was a good chance I would be interested in the Search News Central page so included it in my search results. When i was not logged in Google had no idea who I was so could not use the relationship I have with Search News Central to personalise my results.
The ability for search engines to personalise our search results is only going to increase. The growth of social media and the popularity of free products provided by search engines will provide search engines with increasingly comprehensive information about us and the ability to link that information with the searches we make. In the meantime it is important to be aware that what you see in your search results may not necessarily be the same as what your potential clients and customers see in theirs.