Electronic Meeting Systems (EMS) are designed to enhance group work by leveraging information technology. EMS aims to improve group effectiveness, efficiency, and satisfaction by directly influencing group behavior. The concept of a meeting is broad, encompassing any activity where people come together, whether in the same place at the same time or in different places at different times. The University of Arizona has conducted extensive research on EMS, developing and using both same-time/same-place and same-time/different-place EMS technologies. This research includes two types of studies: developmental, which aims to create improved work methods, and empirical, which evaluates and understands these methods. The research program began with the development of tools and techniques to support groups of analysts. In 1984, a special-purpose meeting room was constructed to support same-time/same-place meetings. This room, along with subsequent ones, is based on networked microcomputer workstations arranged in a U-shape around a table. A large-screen video display is used for meeting guidance, and other audio-visual support is available. The realization that EMS technology could support tasks beyond system development led to the third phase, which began in 1986 with the establishment of four major research projects with IBM. The number of EMS facilities at Arizona increased from one in 1985 to three, with four more scheduled to open later this year. New software, University of Arizona GroupSystems, was developed and installed at EMS facilities at over 22 universities and 12 corporations. IBM has built 36 GroupSystems facilities, with an additional 20 scheduled to be operational by January 1992. Over 25,000 people have used GroupSystems within IBM, and over 3,000 others from 200 organizations have used the Arizona GroupSystems facilities. Another 2,000 have used GroupSystems in over 20 laboratory experiments and 15 doctoral dissertations. EMS supports a variety of tasks, with many groups following a common sequence of use. The group leader meets with a GroupSystems meeting leader/facilitator to develop an agenda and select tools. Meetings typically begin with participants generating ideas, which are integrated and displayed on large screens. Ideas are then organized into key issues, prioritized, and action plans are developed. The result is typically a large volume of input and ideas, and a group consensus for further action. EMS can enable wide participation, leading to broad input, ownership, and consensus. Theoretical foundations of EMS include the idea that EMS design is one of four contingencies (group, task, context, and technology) that affect group meetings. EMS can improve group work by enabling simultaneous participation, equal opportunity for participation, discouraging negative behavior, supporting larger meetings, allowing choice of techniques, providing access to external information, and supporting organizational memory. EMS effects are influenced by four mechanisms: process support, process structure, task structure,Electronic Meeting Systems (EMS) are designed to enhance group work by leveraging information technology. EMS aims to improve group effectiveness, efficiency, and satisfaction by directly influencing group behavior. The concept of a meeting is broad, encompassing any activity where people come together, whether in the same place at the same time or in different places at different times. The University of Arizona has conducted extensive research on EMS, developing and using both same-time/same-place and same-time/different-place EMS technologies. This research includes two types of studies: developmental, which aims to create improved work methods, and empirical, which evaluates and understands these methods. The research program began with the development of tools and techniques to support groups of analysts. In 1984, a special-purpose meeting room was constructed to support same-time/same-place meetings. This room, along with subsequent ones, is based on networked microcomputer workstations arranged in a U-shape around a table. A large-screen video display is used for meeting guidance, and other audio-visual support is available. The realization that EMS technology could support tasks beyond system development led to the third phase, which began in 1986 with the establishment of four major research projects with IBM. The number of EMS facilities at Arizona increased from one in 1985 to three, with four more scheduled to open later this year. New software, University of Arizona GroupSystems, was developed and installed at EMS facilities at over 22 universities and 12 corporations. IBM has built 36 GroupSystems facilities, with an additional 20 scheduled to be operational by January 1992. Over 25,000 people have used GroupSystems within IBM, and over 3,000 others from 200 organizations have used the Arizona GroupSystems facilities. Another 2,000 have used GroupSystems in over 20 laboratory experiments and 15 doctoral dissertations. EMS supports a variety of tasks, with many groups following a common sequence of use. The group leader meets with a GroupSystems meeting leader/facilitator to develop an agenda and select tools. Meetings typically begin with participants generating ideas, which are integrated and displayed on large screens. Ideas are then organized into key issues, prioritized, and action plans are developed. The result is typically a large volume of input and ideas, and a group consensus for further action. EMS can enable wide participation, leading to broad input, ownership, and consensus. Theoretical foundations of EMS include the idea that EMS design is one of four contingencies (group, task, context, and technology) that affect group meetings. EMS can improve group work by enabling simultaneous participation, equal opportunity for participation, discouraging negative behavior, supporting larger meetings, allowing choice of techniques, providing access to external information, and supporting organizational memory. EMS effects are influenced by four mechanisms: process support, process structure, task structure,