Mir Rosenberg from the Bing Mobile Relevancy team posted some of the “factors at play” when it comes to how Bing determines mobile relevance and ranking in the mobile results.

As you know, a couple weeks ago, Bing announced new mobile crawlers to help them discover and understand different forms of mobile content.

Now, Bing is explaining how they determine which mobile sites are relevant for specific queries on top of all of their other relevancy factors. The specific mobile factors Bing shared. Those factors include:

• Identify and classify mobile and device-friendly web pages and websites
• Analyze web documents from a mobile point-of-view by looking at:
  • Content compatibility
  • Content readability
  • Mobile functionality (to weed out “junk”, that is pages that are 404 on mobile or Flash only etc.)
• Return more mobile-friendly URLs to the mobile SERP
• Ranking the results pages based on all of the above

Bing once again strongly recommends Webmasters take the responsive design approach, this way Bing only has one URL, one piece of content, to try to manage. But Bing is actively improving how they handle other forms of mobile content, such as adaptive design, m-dot content and other forms.