The internet — once hoped to infinitely expand our mental horizons and our exposure to challenging ideas — now seems more likely to confine us to our prejudices.
When you search in your web browser today, for any given term, your search engine (Google, for the overwhelming majority of Australians) retrieves pages that it thinks you will be most inclined to take an interest in, based on your personal search and browsing history.
Day by day, with each moment of online interaction, search engines are etching a more detailed portrait of our interests, and filtering out the world beyond those interests.
Personalised search means that when two people type an identical term into google, the results displayed could be quite different. It means, on the plus side, that Google's results are ranked by specific and contextual relevance rather than just by what other people have clicked on.
Meaning, for example, that typing in 'I like' no longer autocompletes to 'I like to tape my thumbs to my hands to see what it would be like to be a dinosaur'.
On the other hand, it could mean that your web history influences your web present.
Personalised searches are not a deliberate attempt to censor information, although search engines have occasionally been found to engage in such practices (see, for example, Siri's suggestions for abortion clinics). Your search is personalised with the best intentions of filtering out the masses of irrelevant information and presenting you with the pages most relevant to you.
And indeed, the results that your search engine provides you with are dependent mostly on your tastes: the pages you have visited, the search terms you use, and links you have clicked.
More recently, Google also incorporates information from your social network (only Google+ at this stage) including links, photos and comments. Google cookies diligently squirrel this information away every time you use the web in an effort to bring you more relevant results next time you search.
Not only your searches are filtered in this way. On Facebook, posts from friends whose viewpoints you share or whose updates you dwell on are privileged to the exclusion of posts that do not interest you.
For me, this means I receive proportionally more content from a younger friend whose posts are so