Yahoo may be behind in the search game, but it could be looking to compete with the likes of Google and Microsoft when it comes to creating a personalized search tool. On an earnings call yesterday, CEO (and former Google executive) Marissa Mayer said that Yahoo was "particularly interested in search in the mobile sector, what happens when you involve context," and it's apparently focusing attention on "what happens when you involve personal information, from things like email." Today, Business Insider reports that a source has provided more details about the project, which is supposedly known as Index.

Index is supposed to be a smartphone app, following up on Yahoo's current Aviate launcher for Android. Aviate acts as a personal assistant using smartphone data and calendar entries, but this would act more like Google Now, mining information from users' inboxes. According to the source, Yahoo is attempting to have a pilot version ready sometime in the second quarter of this year.

"Yahoo has many 20-year-old accounts." On the call, Mayer referred to things like Siri, Cortana, and Google Now as a new and promising kind of search. She said that as mobile moves to "the watch and onto television screens and video," Yahoo wants to help people "make better sense of the content they already have access to, content in their mail," to provide better results. She gave the example of learning that a user had booked a flight from John F. Kennedy Airport, then prioritizing their search to favor practical data and a boarding pass over, say, Wikipedia. Helping users find flight information is a fairly fundamental task for a mobile assistant like Google Now, Siri, or Cortana. According to Business Insider's source, though, Yahoo thinks its advantage lies in sheer longevity:

"Gmail users have only had their accounts for 10 years. Yahoo has many 20-year-old accounts. Back then people used to email themselves a lot — store things. To surface that kind of data usefully is exciting."

Actually, Index is starting to sound less like Cortana and more like Facebook's nostalgia engine.