Including preference in anthropometry-driven models for design

In the design of artifacts that interact with people, the spatial dimensions of the user population are often used to size and engineer the artifact. The variability in body dimensions (called “anthropometry”) is used to indicate how much adjustability or how many sizes are required to accommodate the intended user population. However, anthropometry is not the only predictor of these kinds of interactions. For example, two vehicle drivers with similar body dimensions might have different preferred locations for the seat. The variability not predicted by body dimensions can be considered “preference”. Designing for human variability requires taking into account variation in both preference and body dimensions. Doing this can facilitate the application of design automation tools such as optimization and robust design methodologies, resulting in products that are safer, cost effective, and more accessible to broader populations (including people with disabilities). In contrast, failure to include a preference component can produce misleading results that under- or over-approximate accommodation and prescribe inappropriate amounts of adjustability. A case study is presented to illustrate these points in which several methods of designing for human variability to determine optimum product geometry are demonstrated.