Human memory can be maddeningly elusive. We stumble upon its limitations every day, when we forget a friend's telephone number, the name of a business contact or the title of a favorite book. People have developed a variety of strategies for combating forgetfulness--messages scribbled on Post-it notes, for example, or electronic address books carried in handheld devices--but important information continues to slip through the cracks. Recently, however, our team at Microsoft Research has begun a quest to digitally chronicle every aspect of a person's life, starting with one of our own lives (Bell's). For the past six years, we have attempted to record all of Bell's communications with other people and machines, as well as the images he sees, the sounds he hears and the Web sites he visits--storing everything in a personal digital archive that is both searchable and secure.
Digital memories can do more than simply assist the recollection of past events, conversations and projects. Portable sensors can take readings of things that are not even perceived by humans, such as oxygen levels in the blood or the amount of carbon dioxide in the air. Computers can then scan these data to identify patterns: for instance, they might determine which environmental conditions worsen a child's asthma. Sensors can also log the three billion or so heartbeats in a person's lifetime, along with other physiological indicators, and warn of a possible heart attack. This information would allow doctors to spot irregularities early, providing warnings before an illness becomes serious. Your physician would have access to a detailed, ongoing health record, and you would no longer have to rack your brain to answer questions such as "When did you first feel this way?"
Our research project, called MyLifeBits, has provided some of the tools needed to compile a lifelong digital archive. We have found that digital memories allow one to vividly relive an event with sounds and images, enhancing personal reflection in much the same way that the Internet has aided scientific investigations. Every word one has ever read, whether in an e-mail, an electronic document or on a Web site, can be found again with just a few keystrokes. Computers can analyze digital memories to help with time management, pointing out when you are not spending enough time on your highest priorities. Your locations can be logged at regular intervals, producing animated maps that trace your peregrinations. Perhaps most important, digital memories can enable all people to tell their life stories to their descendants in a compelling, detailed fashion that until now has been reserved solely for the rich and famous.
A Web of Trails
The vision of machine-extended memory was first expounded at the end of World War II by Vannevar Bush, then director of the U.S. government office that controlled wartime research. Bush proposed a device called the Memex (short for "memory extender")--a microfilm-based machine that would store all of an individual's books, records and communications. The Memex was to be built into a desk and equipped with a keyboard, a microphone and several display surfaces. The person behind the desk could use a camera to make microfilm copies of photographs and papers or create new documents by writing on a touch-sensitive screen. The Memex user could also mount a camera on his or her forehead to capture pictures while away from the desk. One of the most prescient of Bush's ideas was the suggestion that the Memex should be designed to imitate the associative thinking of the human mind, which he described in lively terms: "With one item in its grasp, it snaps instantly to the next that is suggested by the association of thoughts, in accordance with some intricate web of trails carried by the cells of the brain."
Over the next half a century intrepid computer science pioneers, including Ted Nelson and Douglas Engelbart, developed some of Bush's ideas, and the inventors of the World Wide Web borrowed the concept of the "web of trails" to build their system of linking sites. But the Memex itself remained technologically out of reach. In recent years, however, rapid advances in storage, sensor and processor technologies have paved the way for new digital recording and retrieval systems that may ultimately go far beyond Bush's vision.