Search 1.0 – pages were ranked based on the how many times the words in the query were on the page. So if you wanted to rank for movies, you’d just put the word ‘movies’ on your page as many times as you could. This of course didn’t always mean the highest quality pages were ranking, so then came the next phase.
Search 2.0 – Link analysis was introduced so there were factors outside the webmaster’s control that affected rankings. Google used link analysis which considered the quality, not just the quantity of links. Also click through rates started to be taken into account to give a higher ranking to pages that users appeared to like.
Search 3.0 – Vertical search was introduced where you can search within specific categories of content e.g. news, scholar, shopping.
Search 4.0 – This is when personalisation came into the picture. Location, search history and social media started being taken into account. Social is growing in importance which gives a lot more power to the people’s opinions.
Search 5.0 – Google is starting to answer questions you search not only with pages results but also their own answer in a box above their results. Danny predicts this will become more advanced to the point where users would almost be able to have a ‘conversation’ with Google, in which Google considers their previous search queries.