Evidence-based design (EBD) is a methodology for the design of health care environments, such as hospitals and clinics, in which decisions about the built environment are based on “credible research to achieve the best possible outcomes.” You might assume that any design activity should be based on empirical data, but the EBD methodology follows a more rigorous process that includes the following:
- Reviewing the existing body of research literature to determine relevant findings and recommendations
- Prioritizing and balancing referenced findings with primary data gathered from site visits, subject matter experts, and stakeholders
- Hypothesizing about the potential outcomes of design decisions, and then tracking those outcomes following design implementation
For example, the design of a new outpatient clinic might begin with a review of published research on outpatient clinic design and of decisions made on similar projects in the past. Followed this would be interviews with the staff (doctors, nurses, administrators) and consumers (patients, family members). The research results would drive the design decisions–for example, the research might determine that there needs to be sufficient collaborative working space in the waiting room for patients and their families. Outcome factors, such as patient satisfaction ratings and waiting time, would also be established and subsequently measured and shared when the clinic is in use.
In most respects, EBD is an idealized version of user-centered design, the widespread practice of integrating user research and usability testing into the design of web sites, software applications, and products. But because EBD is focused on health care environments, it has a centralized, standards-setting organization, The Center for Health Design, and its practitioners have developed a sharable, accessible ongoing body of research work named Healthcare Environments Research & Design Journal (HERD).
In comparison, web, software, and product design are each broader, more diverse fields. While there are publications and conferences for those fields, it’s challenging to find focused sources around the effective design of a specific type of product–versus general design guidelines. And post-launch outcomes measurement, a fundamental activity in EBD, is rarely a required part of any user-centered design process, and it’s rarely shared with fellow practitioners.
Evidence-based design addresses many of the methodological concerns that arise in qualitative, small-sample research, also relevant to product design. For example, EBD makes the valuable point of considering any research method from the perspectives of both objectivity and context. Objective, quantitative methods, such as controlled laboratory studies or surveys, also tend to be the most removed from the actual design context. They provide scientific credibility, but may not account for the specifics of the particular situation. On the other hand, interviews and ethnographic observation–while qualitative–can be performed contextually, and provide deeper detail and relevance, albeit with less scientific rigor. EBD thoughtfully recommends a balance of both kinds of research. The thoughtful planning and the balancing of both qualitative and quantitative methods that EBD advocates may be the strongest takeaway for designers.
For more information on EBD, I highly recommend the succinct and readable Practitioner’s Guide to Evidence-Based Design.
Rob Tannen is an expert in designing
products, interfaces, and systems that accommodate the complexities of
human behavior and capabilities. He has researched cockpit interfaces
for U.S. Air Force, designed trading floor order systems for the New
York Stock Exchange, and created touchscreen applications for consumer
appliances. Rob is Director of User Research and Interaction Design at
the product development firm Bresslergroup. He also has a PhD in human
factors and is a Certified Professional Ergonomist .