Effects of Interruptions, Task Complexity, and Information Presentation on Computer-Supported Decision-Making Performance, The

Decision Sciences, Fall 2003 by Speier, Cheri, Vessey, Iris, Valacich, Joseph S

ABSTRACT

Interruptions are a frequent occurrence in the work life of most decision makers. This paper investigated the influence of interruptions on different types of decision-making tasks and the ability of information presentation formats, an aspect of information systems design, to alleviate them. Results from the experimental study indicate that interruptions facilitate performance on simple tasks, while inhibiting performance on more complex tasks. Interruptions also influenced the relationship between information presentation format and the type of task performed: spatial presentation formats were able to mitigate the effects of interruptions while symbolic formats were not. The paper presents a broad conceptualization of interruptions and interprets the ramifications of the experimental findings within this conceptualization to develop a program for future research.

Subject Areas: Decision Making, Interruptions, and Information Presentation Formats.

INTRODUCTION

You are sitting at your desk working on a financial analysis or marketing report that is due tomorrow, when the phone rings. After taking the call, you return to your project only to discover that three e-mails have come in while you were on the phone and one is marked a priority. Will these interruptions affect the quality of your project deliverables? If so, are there features that can be designed into information systems that mitigate interruption effects?

Both the academic and popular presses have concluded that interruptions permeate knowledge-worker environments (Mintzberg, 1973; Markels, 1997; Schmandt, Marmasse, Marti, Sawhney, & Sheeler, 2000). Knowledge workers perform a stream of disjointed activities (Carlson, 1951; Guest, 1956; Stewart, 1967) that occur at an unrelenting pace (Kurke & Aldrich, 1983; Mintzberg, 1973). Carlson (1951), examining the work life of managers, stated "All they knew was that they scarcely had time to start on a new task or sit down . . . before they were interrupted by a visitor or a telephone call" (pp. 73-74).

More recent studies continue to highlight the relationship between interruptions and knowledge-worker activities. For example, telephone interruptions and drop-in visitors have been identified as significant corporate time-wasters (Dahms, 1988), which knowledge workers often allow to take precedence over other activities (Jones & McLeod, 1986; Watson, Rainier, & Koh, 1991). E-mail interruptions may be more prevalent than phone and human interruptions, with studies reporting that knowledge workers in the United States send and receive an average of 204 emails per day (Pitney Bowes, 2000) and experience an average of six interruptions per hour in a typical work day (Pitney Bowes, 1998). Other evidence demonstrates that managers spend 10 minutes of every working hour responding to interruptions and do not return to their initial task 41% of the time (O'Conaill & Frolich, 1995). Thus, an interrupted work environment is commonplace for a typical knowledge worker.

Information systems are used increasingly to support knowledge-worker decision-making tasks, particularly when solving complex problems (Panko, 1992). These complex tasks typically involve high cognitive loads that require significant mental attention and effort and might therefore be susceptible to interference from interruptions (Baecker, Grudin, Buxton, & Greenberg, 1995). Further, "productivity" tools used in many organizations can actually instigate task interruptions-that is, e-mail or instant messaging services (Markels, 1997). Similarly, the spread of mobile telephones has brought with it the potential for continual interruptions from unwanted or ill-timed phone calls (Schmandt et al., 2000).

Given the detrimental influence of task complexity on computer-based decision making (Robinson & Swink, 1994; Grassland, Wynne, & Perkins, 1995; Swink & Robinson, 1997) and the likely negative influence of interruptions (Cellier & Eyrolle, 1992; Shiffman & Griest-Bousquet, 1992; Schuh, 1978), an important question is whether information systems can be designed to mitigate these effects (Rouncefield, Viller, Hughes, & Rodden, 1995). Prior research has identified information presentation as a factor affecting decision performance (DeSanctis, 1984; Tan & Benbasat, 1990; Vessey, 1991). Given the ease of changing presentation formats in most productivity-enhancing software packages, we focus on information presentation as a mechanism to help overcome these challenges. Understanding if and how information presentation formats can mitigate interruptions is therefore important to both designers and users of packaged software.

THEORY DEVELOPMENT AND HYPOTHESES

Interruptions have been defined as uncontrollable, unpredictable Stressors that produce information overload, requiring additional decision-maker effort (Cohen, 1980). In addition, interruptions typically "require immediate attention" and "insist on action" (Covey, 1989, pp. 150-152). Thus, another person, object, or event creates an interruption, the timing of which is beyond a decision maker's control. Furthermore, an interruption breaks a decision maker's attention on a primary task and forces the decision maker to turn his or her attention toward the interruption-if only temporarily.