Before mobile devices were available, we generally studied behavior by asking participants what they did, sometimes a long time after they did it. For some behaviors, this is less than ideal, since many of the details can be hard to remember. In this study, we asked participants to keep a "diary" of their behaviors on their mobile phones over 30 days, and asked them to report on a variety of behaviors (e.g., their drinking, drug use, and sexual activity) each day during that time.
This study shows that doing so is feasible and acceptable for most gay/bisexual men, since most regularly use smartphones already. As a bonus, most also carry these devices with them everywhere, meaning that they may be able to remember more accurately than other methods, since they can describe the details in the moment these behaviors happen. Our findings showed that, in a small group of participants, reporting on these behaviors via their smartphones may yield more accurate data than asking them even 30 days later. This is especially important because we're interested not just in what happened, but when.