Email is a ubiquitous communications tool in the workplace and plays an important role in social interactions. Previous studies of email were largely based on surveys and limited to relatively small populations of email users within organizations. In this paper, we report results of a large-scale study of more than 2 million users exchanging 16 billion emails over several months. We quantitatively characterize the replying behavior in conversations within pairs of users. In particular, we study the time it takes the user to reply to a received message and the length of the reply sent. We consider a variety of factors that affect the reply time and length, such as the stage of the conversation, user demographics, and use of portable devices. In addition, we study how increasing load affects emailing behavior. We find that as users receive more email messages in a day, they reply to a smaller fraction of them, using shorter replies. However, their responsiveness remains intact, and they may even reply to emails faster. Finally, we predict the time to reply, length of reply, and whether the reply ends a conversation. We demonstrate considerable improvement over the baseline in all three prediction tasks, showing the significant role that the factors that we uncover play, in determining replying behavior. We rank these factors based on their predictive power. Our findings have important implications for understanding human behavior and designing better email management applications for tasks like ranking unread emails.
Information overload in email was studied since the 90's. In contrast to Whittaker and Sidner @cite_28 , who defined as the use of email as a tool for task management, archival, and communication, we follow the definition of overload as not being able to keep up with the volume of incoming email @cite_5 @cite_24 . Unlike previous qualitative studies that focused on the perception of overload @cite_5 , we focus on quantitative measures of overload and its observed effects on users' behavior.
@cite_28 @cite_5 @cite_24
2004184082 2052742498 2155656311 2137891816
Ten years ago, Whittaker and Sidner [8] published research on email overload, coining a term that would drive a research area that continues today. We examine a sample of 600 mailboxes collected at a high-tech company to compare how users organize their email now to 1996. While inboxes are roughly the same size as in 1996, our population's email archives have grown tenfold. We see little evidence of distinct strategies for handling email; most of our users fall into a middle ground. There remains a need for future innovations to help people manage growing archives of email and large inboxes. Almost every office worker can relate to feelings of email overload and stress, but in reality the concept of email strain is not well understood. In this paper, we describe a large-scale nationwide organizational survey examining the relationship between email use and feelings of email overload and task coordination. We found that higher email volume was associated with increased feelings of email overload, but this relationship was moderated by certain email management strategies. The contribution to the field of CSCW is a better understanding of the concept of email related stress, and initial scale development for the assessment of email-related overload and perceptions of the work-importance of email. We report on an empirical study where we cut off email usage for five workdays for 13 information workers in an organization. We employed both quantitative measures such as computer log data and ethnographic methods to compare a baseline condition (normal email usage) with our experimental manipulation (email cutoff). Our results show that without email, people multitasked less and had a longer task focus, as measured by a lower frequency of shifting between windows and a longer duration of time spent working in each computer window. Further, we directly measured stress using wearable heart rate monitors and found that stress, as measured by heart rate variability, was lower without email. Interview data were consistent with our quantitative measures, as participants reported being able to focus more on their tasks. We discuss the implications for managing email better in organizations. Email is one oftl most successful computer applicmiom yet devised. Our empin :al ct ta show however, that althongh email was origiraUy designed as a c nmunica ons application, it is now used for tional funaions, that it was not designed for, such as tab management and persona afoOt v rig. We call this ernt l oveHoad We demonstrate that email overload creates problems for personal information manageaa,cnt: users eden have cluttered inboxes cor mining hundreds of n :age ¢, incl rling outstanding tasks, partially read documents and conversational threads. Furthermore,, user attemt:Xs to rationalise their inbox by ing are Ron unsuccessful, with the consequence that important rr ges get overlooked, or "lost" in archives. We explain how em l over oad ng arises and propose technical solutions to the problem.