What is Evidence-Based Design?
The medical field is a useful resource for consideration by product researchers and designers. The combination of rigorous, but varied procedures, and focus on measurable outcomes lends itself to efficient and effective practices. For instance, a few weeks ago I discussed the success of checklists in surgical contexts and their potential application as a format for design recommendations & guidelines.
Evidence-based design (EBD) is another important methodology that stems, not directly from the medical field, but from architecture and the design of healthcare environments. While one might think that any design process should be, or at least could be, based on evidence, the term "evidence-based design" is specific to the "process of basing decisions about the built environment on credible research to achieve the best possible outcomes."
The goals and methods of EBD should be quite familiar to anyone experienced with the scientific method, but because the approach accounts for qualitative as well as quantitative research and data analysis, it is highly relevant to user research in product design. The basic approach of EBD 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
A simple example in the context of a healthcare environment design (e.g. a new outpatient clinic), might begin with a review of published research on outpatient clinic design as well as reviewing decisions made on similar past projects. The Center for Health Design provides references to extensive resources for evidence-based design. Then conducting interviews with the staff (e.g. doctors, nurses, administrators) and consumers (e.g. patients, family members). The results from this research would drive the design decisions - for example, to provide 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.
Evidence-Based Design and Qualitative Data
One reason I consider EBD valuable to product designers is that the EBD research approach accounts for many of the methodological concerns that arise in qualitative, small-sample research. Evidence-based design makes the valuable point of considering any research method from the perspectives of both objectivity and context. That is, the most objective, typically 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, albiet with less scientific rigor. EBD recommends a balance of both kinds of research to provide the best data set, and also discusses how to blend the two approaches - for example gathering quantitative data about patient movement while conducting observational research.
Similarly, EBD discusses how to handle apparently conflicting or contradictory research findings. Such situations are an opportunity to examine the root causes of the differences - for example did two similar studies provide contrasting results due to differences in the populations studied, or the particulars of data collection?
In other words, the EBD research approach is a realistic and pragmatic one. The mindset of gathering different types of data from different sources and then looking at the findings across the data sources is comparable to the triangulation approach that I employ in product design research.
Evidence-Based Design Vs. User-Centered Design
Presumably any product or interface design practitioner who has read this far would be wondering how evidence-based design relates to user-centered design. In both methodologies, the goals are very similar - apply appropriate design principles to create effective, usable results. And while there is overlap between the two fields, their are also significant differences in their details. In fact, there are at least two critical differences between how evidence-based and user-centered design are practiced:
- Published Research - In EBD, there is a focused effort to document the best practices for healthcare environment design via journals, such as Healthcare Environments Research & Design Journal (HERD). In comparison, product design is a much broader, diverse field, and while there are publications and conferences, it is challenging to find focused sources around the effective design of a specific type of product, versus general guidelines for product design (e.g. ergonomics, human-computer interaction guidelines).
- Outcomes Measurement - A critical goal for EBD is the definition and measurement plan for evaluating the outcomes of the design. These are often based on clinical results and patient/staff satisfaction. Direct outcomes measurements is rarely a part of any user-centered design process. In product design, outcomes may be estimated prior to implementation through usability testing (an activity seemingly not given significant attention in EBD), and occasionally via post-launch evaluations.
Adapting Evidence-Based Design Methods to Product Design
It's a given that increasing the integration of published research and outcomes measurement would benefit the product design field. But I expect the reality of that will vary greatly with the particular types of products. Consumer-focused areas like electronics and computers will likely remain relatively closed for competitive reasons.
Medical product design would be an appropriate area to apply EBD methods. It already has the obvious connection with the medical field, and with that come some of the necessary resources. For instance, both ergonomic/human factors periodicals (example here) as well as specialized medical journals (example here) address the effectiveness of tools for the growing field of tool design for laparoscopic surgery. These articles address the effectiveness of tools from both the design and clinical outcome perspective, although require some learning & effort to understand the specialized vocabularies.
But finding appropriate reference information is only half the story. Research is a cyclical process where those taking guidance from previous research must disseminate their own findings. This may be done formally, through the journals and conferences, or informally via blogging or trade group meetings. For example, the interaction designers association, while focused on interface design, is a great model of an online community sharing best practices and guidance for design on an as-needed basis. This bottom-up information distribution is also see in social/professional networking sites such as the Medical Devices Group on LinkedIn.
More generally, the thoughtful planning and balancing of qualitative and quantitative methods advocated for in evidence-based design may be the strongest takeaway for product designers.
In the future, I expect that environmental designers/architects and product designers will work more closely in shaping the entire user experience. In such an integrated approach essentially every detail of the healthcare provider's and patient's experience will be considered - from the layout of the room to the ergonomics of a medical instruments to the usability of healthcare information systems - rather than designed as independent objects that must co-exist within the same system.
For more information on Evidence-Based Design, I highly recommend the succinct and readable Practitioner's Guide to Evidence-Based Design (pictured above).