Int. J. Human—Computer Studies (1998) 48, 763—776 Replying to email with structured responses BEATRICE M. CAMINO,ALLEN E. MILEWSKI,DAVID R. MILLEN AND THOMAS M. SMITH AT&T Laboratories, 100 Schulz Drive, Red Bank, NJ 07701, USA (Received 2 June 1997 and accepted in revised form 27 February 1998) Structured response objects include buttons, menus and formatted fields that an email sender can insert in a message to elicit predetermined responses from recipients. Two studies explored the usefulness of structured response objects in meeting the needs of everyday email. In Study 1, subjective content classifications suggested that more than half of typical email messages are requests or answers to requests. Further, a significant proportion of requests and answers could be expressed as structured response objects, the most common one being the choice of a single item from a predetermined list. Study 2 experimentally determined social factors that affect preference for structured responses compared with free form text. It found an overall preference for replying with structured responses compared with text. But, in accordance with social richness theories, this preference was reduced for ambiguous messages and for those of a personal nature. Together, these results suggest that structured response objects can be a useful tool to increase the convenience and efficiency of electronic messaging. 1998 Academic Press Introduction As the popularity of electronic mail has grown, so has the number of messages sent and received by its users (Sproull & Kiesler, 1991; Markus, 1992). The number of email messages is expected to increase even more over the next several years (Rudy, 1996). Because of the large amount of mail received, there is now substantial attention being paid to methods for increasing the efficiency of processing and organizing messages. One of the methods receiving attention is the ‘‘structured response object.’’ Structured response objects include buttons, menus, formatted fields and other objects that the sender can include in the body of the message, and that can trigger a variety of functions when manipulated by the recipient. Several commercial email systems (e.g. Lotus Notes and Microsoft Exchange) allow the sender to specify a ‘‘form’’ that recipients can fill out, thus imposing an a priori structure on the reply. In addition, computational email prototypes that can embed capabilities, including form-rendering, within a message, also afford structured responses (Lai, Malone & Yu, 1988; Borenstein, 1992). There are reports that in some organization-wide situations, the use of structured response objects can result in real efficiencies (Gates, 1995). They can reduce the amount of time and effort spent by the recipient while responding to the message. In many structured response cases, the recipient can simply click the mouse once and the message is answered in a meaningful way. Also, because structured responding can enforce more consistency in the reply content, these objects can help the sender and recipient to organize, filter and potentially perform automatic processing on the replies. By pre- specifying appropriate responses, some of the communications burden typically assumed 1071-5819/98/060763#14$25.00/0/hc 980187  1998 Academic Press