Have you always wondered how Google goes about displaying its search results? How many steps there are between user input and the web results actually becoming visible? In a new podcast episode of Google “Search off the Record” they have now spoken in detail and explained how it actually works.
Although Google doesn’t let you look at its cards when it comes to ranking search results, the way it works is explained quite clearly in the latest Google Podcast.
Each search query starts with entering the search term
The user enters a search term into Google’s search mask. The search query then passes through Google’s systems in two directions: first downwards, then upwards again. On its way down, the search query passes through several systems. One of them is responsible for parsing, i.e. processing and understanding the search query.
This is followed by a kind of router. It ensures that the search query reaches the various indexes. This step is important for the so-called Universal Search, i.e. search result pages with different types of results. Here, for example, suitable news, videos and images are picked out.
In the case of web search, the parsed search query now moves into the delivering index. Here, some things happen that Google does not go into further. On the basis of the posting list, results are generated that could match the respective search query. Accordingly, Google selects the matching results and pushes them back to the top. This is where the ranking system comes into play, which sorts the results.
The application of ranking signals to a search result
Next, well-known criteria such as relevance to a topic, quality of content, and another hundred ranking factors are included and applied. From here, the search results continue to move up and once again reach a router that has sent the search queries to different layers of the index. At this point, results from other indexes are waited for, if these search results are played out in a given time, they are mixed in with the search results.
If the other results do not arrive in time, they are omitted. For example, Google Maps is not considered critical, so if there is no timely response here, these results are not played out. The exception is the web results – they are always waited for.
Another important role: caching. If someone searches for a specific item nearby, they will most likely always be directed to the same data center because of the geographic location. After the first search query, content would be loaded from the cache for further identical search queries, so that not all the steps described above are run through, which in turn leads to faster playout of the results.
All in all, Google does not show its cards with regard to the application of the ranking factors, but nevertheless provides a clear insight into how search results are selected.