A methodology for controlled empirical investigation of membership continuity and change in group decision support systems groups

Controlled laboratory experiments using monetary rewards tied directly to performance are detailed and illustrated, as part of a methodology for investigating how membership continuity and change affect group meeting performance, solution time, and productivity. Performance-based rewards were structured to induce subject attendance and to prompt subjects to contribute their best effort. A key element of our methodology is the ability to successfully conduct longitudinal studies. We illustrate the methodology in an example study of groups of size three and groups of size five. Experiments are carefully monitored and controlled as a means to begin development of a set of consistent and comparable investigations, of groups of differing sizes and differing levels of membership continuity and change. The initial experiments yielded results formally verifying that membership continuity produces better meeting outcomes (increased performance and productivity, and decreased solution time) while membership change produced the exact opposite (decreased performance and productivity, and increased solution time). Drawing from philosophy of science, we emphasize the importance of carefully checking and verifying in a longitudinal study even what some might suggest as ‘obvious’.