Following up on our recent release of a long-delayed tech report on social ranking of email search, another news article recently highlighted a similar approach to a different aspect of the problem, socially sorting incoming email.

In either case, there’s a crying need for smarter email clients (at least, for us few doddering old souls who live and die by email — apparently, few creatures under 18 have ever heard of the medium, between their gum-chewing, IMing, and illegal downloading…). As Microsoft Research sociologist Marc Smith points out in the news report on the SNARF system, there’s already an immense reservoir of personal behavioral information on the average PC hard drive. Taking advantage of this information to surface implicit relationships between correspondents, whether based on a graph analysis (as our KudoRank proposal does); interaction timelines (apparently a key part of SNARF and its USENET predecessor, NetScan); or the kinds of vocabulary and relationships used (Andrew McCallum‘s Author-Role-Topic model); are all signs of a trend to put the vast computing resources available today to work on the treacherous problem of getting computers to read email for us :)


SNARF begins indexing e-mail messages on initial launch. Once it’s finished indexing, it shows a window with three panes.

  • Top pane: People who have sent recent e-mail addressed or cc’d to the mailbox owner. Messages are unread.
  • Middle pane: People who have sent recent, unread e-mail addressed to anyone.
  • Bottom pane: All people mentioned in any e-mail the mailbox owner has received in the past week.

SNARFing your way through e-mail
By Ina Fried
Story last modified Fri Dec 02 04:00:00 PST 2005

With the world’s in-boxes overflowing with unread messages, researchers at Microsoft are offering up a tool they hope will help people sort through the morass.

The software maker this week released a free utility that aims to sort e-mail in a new way: It can organize messages not just by how recent they are, but also by whether the recipient knows the sender well.

The program, known as SNARF, bases its approach on the fact that people tend to interact more with messages from those they care about.

“You don’t respond to everybody, and not everybody responds to you,” said Marc Smith, one of the Microsoft researchers who developed SNARF, or Social Network And Relationship Finder.

Though SNARF is a research project for now, Microsoft said that similar features could soon make their way into its e-mail products.

Smith boils it down this way. His computer, for all its power, serves up his e-mail without distinguishing junk mail from messages sent by close friends. His dog, on the other hand, learns who his friends are and stops barking at them.

“If my dog can tell who strangers are, apart from friends…my e-mail reader should be able to do the same,” he said.

The task is increasingly important as people become overloaded with e-mail. Though many like to be alerted to new messages, the barrage of notifications is now so frequent for many workers that it is nearly impossible to get any creative work done without being interrupted.
SNARF screenshots

“The machines got us into this problem,” Smith said. “They are going to have to get us out of it.”

Smith calls today’s method of sorting e-mail the “ADD sort order,” in which the newest messages are constantly presented first, regardless of who sent them. There has to be a better way, he said.

Figuring out who your friends are may not seem like a task well-suited to computers, but Smith said it’s simply a matter of making sure that the computer is adding up the right things.

“The beautiful thing about computers is that they are really, at their core, accounting machines. They love to count things. Social relationships are countable,” Smith said.

In SNARF’s case, the software looks at how often people correspond with particular content in the body of a message and how often they reply to one another’s correspondence, among other things.

The concept is not new. The idea of “social sorting” has been explored by Microsoft and others for years. Researchers at Hewlett-Packard, for example, looked at the patterns of who e-mailed who within HP Labs. Doing so, the researchers found, turned out to be a more effective means of determining working groups than looking at an organizational chart.

Microsoft has also used social sorting to help users wade through Internet forums, in a research effort known as NetScan.

Smith points out that our PCs already know tons about us, in many cases storing years’ worth of messages and replies. “This is more than the diarists of the 17th and 18th centuries,” he said.

SNARF can also sort messages based on whether they were sent directly to you, whether you were copied on the message or whether you were part of a distribution list.

While such an approach can help sort through the sea of messages, it’s not flawless. Smith noted that not everyone who is important to him returns his e-mails.

“My mother, I’m sorry to say, just never replies to my e-mail,” he said, quickly noting that it’s no reflection on the quality of his relationship with her.

Smith said there is a strong chance the social sorting techniques will find their way into Microsoft products. There have been feelers from the teams responsible for Outlook, Exchange, Hotmail and Outlook Express, he said.

“We’re having lots of meetings with people,” Smith said.

For now, the research team has put its software out there as a download for people to experiment with. Officially, Microsoft says SNARF will definitely work with Outlook 2003 and Windows XP Service Pack 2, though Smith said it may work with other software. SNARF also requires the .Net framework, though it will install it if a computer does not already have the operating system add-on.

Smith is also working on expanding the research project in several ways. For example, the current version cannot be customized so that a user can say that a certain friend is important, even though they only exchange e-mail once a year.

Allowing users to “tag” e-mails in various ways is among the features that the company is looking at. “We are exploring a range of ideas around that,” he said. “It’s a very important direction,” he added, noting that the next version of Outlook also includes new tagging capabilities.

Moving onto cell phones would be another good move for SNARF, he said. “If you are not at your computer to do triage, having 150 e-mails can be daunting,” he said. “It would be nice to have the seven e-mails from colleagues in a separate folder.”