Google is still working on their mobile search index, something Google first confirmed last year, although we haven’t heard much about it for a year or so.  The mobile index would be completely separate from the desktop index and would be for searches done on mobile only.

Why is Google working on a mobile only index?  Gary Illyes from Google was speaking at Search Marketing Summit in Sydney and said while desktop was still the majority of searches, it didn’t make sense to use a mobile index.  But now that mobile is more than 50% of searches it makes much more sense.

Illyes said that there are some problems with a mobile index.  When they convert parts of the index from a desktop one to a mobile one, there is a loss of tokens that affects the rankings, which means that there is an issue with ensuring sites are ranking the same with the loss of those tokens.  According to Illyes, “We are losing signals when we convert parts of our index into mobile index because there are fewer tokens on the page.”

Links

People don’t link to mobile content as much as they do to desktop content.  Google found there are fewer linking rank signals on mobile pages when compared to the desktop equivalent.  So this results in pages ranking differently when compared to the desktop index.  This was one of the main problems Google found last year while working on the mobile index.

On Page Content

Mobile specific pages are often shorter or truncated when compared to the desktop version.  This is pretty common, especially for m. mobile sites where there are two pages (canonicalized) for the same article, just one is not quite as comprehensive as the other.  But according to Illyes, the content changes is also impacting rankings as well.  that said, it is sometimes frustrating from a user perspective when you land on a truncated mobile page that doesn’t actually have the information you are looking for, because it is only on the desktop version.

Google has been working on the mobile index for two years, and Illyes said they aren’t quite there yet.  Google publicly confirmed the mobile only index last year, and released some more details on it.  So while we might not have a more definitive answer a bout when we might see it, it is good to know that Google is continuing to work on it.