Bob Evans has spent most of his life obsessing over how to track data. When the Google software engineer was a boy in Louisville, Kentucky, he collected star stickers to show that he had done his chores. In college, where he studied philosophy and classical guitar, Evans logged the hours he spent playing music. Later, as an engineer for a Silicon Valley software company, he defended his dog, Paco, against a neighbor’s noise complaints by logging barks on a spreadsheet (the numbers vindicated Paco, showing he was not the source of the public disturbance). For Evans, collecting data has always been a way to keep tabs on his habits, track his goals, and confirm or dispel hunches about his daily existence.
Last May, Evans reminisced about those early days in data collection as we sat in a large-windowed conference room in Building 47 of the Google campus, near San Jose, California. His personal fixation is shared by a growing number of self-trackers, a movement that is spreading far beyond data-obsessed engineers. Taking advantage of new wearable wireless devices that can measure things like sleep patterns, walking speeds, heart rates, and even calories consumed and expended, more and more people are signing up to download and analyze their personal data. Nearly 10 million such devices will be sold in North America in 2011, according to the market forecasting company ABI Research.
Most self-trackers are extreme fitness buffs or—like Evans—technology pioneers inherently interested in novel software applications. But Evans believes that personal data collecting could have stunning payoffs that go beyond just taking a better measure of everyday behavior. Already, some proponents claim personal benefits from logging their habits—eliminating foods that trigger migraines or upset stomachs, for instance, or saving certain tasks for their most productive time of day. Applied more broadly, data collected by self-trackers could help them find better treatments for diseases and even predict illness before symptoms become obvious.
Evans also sees the potential for individual citizens to pool nonmedical data collected through tracking experiments. Such data sets could have important social benefits. For instance, if members of a community tracked their feelings about safety in their neighborhood and shared their data regularly, crime trends could be detected earlier and addressed more effectively.
As Evans’s history with data collection shows, basic self-tracking is possible with nothing more than a pencil and paper. Still, people have been reluctant to sign on to an activity that has historically required inordinately high levels of self-curiosity and motivation. Now, with the wildfire spread of smartphones and tablet computers, that resistance could be melting away—and Evans plans to capitalize on the change. He has developed a tracking tool, conveniently contained in a mobile phone app, that he thinks can make self-tracking appealing to the masses.