A Model of Your Inbox

I've been thinking a lot about how users view and manage their inbox. This post is about the model I came up with. I'm basing this on my own experience and on having talked to dozens of people about their email habits. But since this blog also is read by lots of email enthusiasts, I'd love to hear your feedback: Does this make sense? What am I missing?

Four Quadrants

Every single email message youreceive can be classified into one of the four quadrants below. Important emails are the ones you need to take action on. Urgent emails are time-sensitive. Urgency does not necessarily imply importance: Your coworker's cake will be gone in a few minutes, but it's not necessary to take action on that, especially if you're on a diet.


The key insight here is that the stuff you care about are the emails on the left. These are the emails that make it worth checking your Crackberry every few minutes. They emails that keep you awake at night.

Filtering the Important

How can you filter out what's important? My theory is that for humans, that's actually the easy part: You often easily determine importance by just looking at the sender of the message. Roughly, senders fall into three categories:

1. Crap: these are easy to remove: iTunes Receipts, Amazon notifications, LinkedIn emails, frequent flier statements, and the like. Not important.


2. VIPs: You know who they are! Major customers, your manager, and your girlfriend belong in this category. Important.


3. People you know: These are the non-VIPs that you still want to deal with. I like to think of this category as the intersection of your Facebook and LinkedIn connections. Mostly Important.


4. Everyone else: Recruiters and salespeople, senders you don't recognize. Mostly not important.

Research indicates that people use senders as their main importance indicator [1, 2]. The task of filtering out important email is easy, and you could probably train a classifier to very high degrees of accuracy.

Managing Later vs. Now

I believe that this is the heart of email overload. Remember how I said that the left side is what matters. I like to label the two subcategories as "Later" and "Now" [3].


The workflow should be that you decide whether you want to deal with an email now or later. You respond to the "now" emails and they disappear into the archive. The "later" emails haunt you until you're done with them.

This is the point where today's email clients fail. Users try various mechanisms to manage now/later and to do/done: Keeping emails unread, starring them in Gmail, and filing away stuff that is done into an intricate foldering system. The number of email management strategies that users come up with impressive [4].

But none of this works. Emails that are unread and starred disappear from your main view. Out of view, out of mind. Poof. There is no pressure to act upon them. In contrast, filing away emails that are done requires an amount of discipline that few users have. I think that the inability of managing now/later and to do/done is one of the main reasons for email overload.

Wrapping Up

Let's review. I've outlined three theories here:

1. Your incoming all fall into one of the four quadrants of urgency and importance. What really matters is the important stuff, which breaks into "Later" vs. "Now".


2. It's easy to filter important vs. not important.


3. It's hard to manage Later vs. Now because the current tools are broken.

I'd love to hear your views on my theories. Drop me a line or leave a comment.

References

[1] Gina Danielle Venolia, Laura Dabbish, JJ Cadiz, and Anoop Gupta. Supporting email workflow. Technical report, Microsoft Research - Collaboration and Multimedia Group, September 2001.

[2] Olle Baelter and Candace Sidner. Bifrost inbox organizer: giving users control over the inbox. In NordiCHI '02: Proceedings of the second Nordic Conference on Human-computer interaction, pages 111-118, Aarhus, Denmark, 2002.

[3] The "Getting Things Done" school of thought has a more intricate system than this, but I think that Later / Now is the essence of it.

[4] Steve Whittaker and Candace Sidner. Email overload: exploring personal information management of email. In CHI '96: Proceedings of the SIGCHI Conference on Human Factors in Computing Systems, pages 276-283, Vancouver, British Columbia, Canada, 1996.