Empirical work in design science has highlighted that the process of ideation can significantly affect design outcome. Exploring the design space with both breadth and depth increases the likelihood of achieving better design outcomes. Furthermore, iteratively attempting to solve challenging design problems in large groups over a short time period may be more effective than protracted exploration by an isolated set of individuals. There remains a substantial opportunity to explore the structure of various design concept sets. In addition, many empirical studies cap analysis at sample sizes of less than one hundred individuals. This has provided substantial, though partial, models of the ideation space. This work explores one new territory in large scale ideation. Two conditions are evaluated. In the first condition, an ideation session was run with 2400 practicing designers and engineers from one organization. In the second condition 1000 individuals ideate on the same problem in a completely distributed environment and without awareness of each other. We compare properties of solution sets produced by each of these groups and activities. Analytical tools from network modeling theory are applied as well as traditional ideation metrics such as concept binning with saturation analysis. Structural network modeling is applied to evaluate the interconnectivity of design concepts. This is a strictly quantitative, and at the same time graphically expressive, means to evaluate the diversity of a design solution set. Observations indicate that the group condition approached saturation of distinct categories more rapidly than the individual, distributed condition. The total number of solution categories developed in the group condition was also higher. Additionally, individuals generally provided concepts across a greater number of solution categories in the group condition.
The indication for design practice is that groups of just under forty individuals would provide category saturation within group ideation for a system level design, while distributed individuals may provide additional concept differentiation. This evidence can support development of more systematic ideation strategies. Furthermore, we provide an algorithmic approach for quantitative evaluation of variety in design solution sets using networking analysis techniques. These methods can be used in complex or wicked problems, and system development where the design space is vast.