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.

Most self-tracking devices currently on the market measure only a few data points and have their own proprietary software and code limiting how users can analyze their own metrics. Evans’s app is different: It can be set up to track any kind of behavior or event and keeps data in one place, making it possible to analyze it all together. It is also designed to address another major objection to such detailed self-reporting, the fear that our personal data could too easily be leaked, stolen, or simply exposed to the public.

My visit to Google was a chance to understand Evans’s vision and to try out its practical application. I’m not a data obsessive by any means. If Evans could convert me, self-tracking just might be for real.

In 2009, while Evans was working for Google to help create new tools to increase programmers’ efficiency, he realized no one was working on the “soft science” side of the equation to help the programmers become more productive in their personal behavior. In his data-oriented way, he set out to understand everything that happens in a programmer’s work life. He wondered how attitudes toward food, distractions, and work environment—sampled throughout the day
—might affect creativity. If a programmer was stressed out or unhappy with a project, could a glance at her daily stats help set her right? Could immediate insight from a survey encourage her to make a change for the better? Evans had a hunch that by gathering the right data sets, he could help people improve their job performance in real time.

To make this process as simple as possible, Evans decided to collect the data through the smart cell phones that Google employees already kept close at hand. He set up an app so a programmer’s phone would chime or buzz a few times throughout the day at random times, as if a text message had arrived. When the employee clicked the message open, the app would ask her if she felt passionate and productive about her project. If not, it asked what she could do to change it.

In addition to gathering data about work habits, Evans set up another survey that asked programmers to outline their work goals. When the app checked in later, it listed those goals and asked which one the programmer was engaged in—the idea being that if a programmer had been distracted, a reminder of what she wanted to accomplish might improve her focus. “I thought it would be cool to build a platform that was not just for collecting data,” Evans says. “It could have the tools and interventions so people could do their own self-improvement.”

The survey was rolled out two years ago to a small number of programmers at the Google campus. Although Evans worried that the app would be too intrusive, he was heartened to see that most programmers continued to use it even after the pilot program officially ended. Since each programmer had different goals, measuring the overall effectiveness of the app was difficult, Evans says, but subjectively, he and his colleagues felt the simple act of observing their behavior through the app led them to change in ways that helped them meet their work goals.