Evidence,Decisions,Guidelines,and Standards

Are Decisions Ever Truly Rational?

Rational decision making would appear to be the logical outcome of an evidence-based process. Decisions based on careful interpretation of credible evidence would seem to help us avoid subjective, intuitive, emotional, or purely aesthetic decision making. For some who observe that architecture lacks rigor, rationality is a positive goal. Yet architecture has always been a blend of science and art. I believe it always will be.

Making decisions is a fascinating capability of the human brain, and our brains use a wonderful mix of rational (neocortex) and emotional (limbic) processes to make decisions. The rational factors are more readily accessible to being put into language, and so we tend to be more aware of them. But the emotional factors drive the bus. (A. Kruse, JD, MSOD, personal communication, February 24, 2009)

So while we yearn for answers to important questions and for guidance at critical moments in the design process, not all decisions can be expected to be rational. Furthermore, some decisions we believe to be rational certainly have been influenced by our subconscious emotional responses. Neuroscience tells us that there is no such thing as a totally rational decision (Lehrer, 2009). Many in the design professions would argue that irrational or emotionally intuitive decisions are frequently those that produce the highest quality architecture and design. Such people would argue against any limitation on the freedom to perform design in their own individual and idiosyncratic way.

What Is the Role of Standards…

… in a field that demands both rigorous and artful decisions? Many who practice or employ design are eager for strong, credible evidence that can lead to reliable guidelines and standards. Strong guidelines can simplify decisions and codify best practice in a way that satisfies our rational brains. When I was in architectural practice, I had health system clients who initially expected that design professionals who relied on evidence would be able to produce readily available answers to their problems. These clients did not realize that evidence-based design is a process, not a product. While it is tempting to believe that an exhaustive search of the relevant literature, careful interpretation of the implications of the research, the development of related and derivative design concepts, the construction of a physical structure, measurement of the associated outcomes, and a subsequent published report lead to certainty about a topic, such confidence may be premature.

The evidence in every field—especially in medicine—is constantly evolving and growing, so rigid standards based on findings that can easily be superseded are likely to be inappropriate. The evidence from environment-behavior studies and many types of social science research in complex, multivariable settings is often less conclusive than the quantitative studies one associates with medicine and the hard sciences. Evidence applied to one situation may produce a completely different recommendation in another situation. These factors weigh against premature conclusions and therefore against restricting design professionals and their clients with guidelines, standards, or codes based on limited information. For this reason, the board of The Center for Health Design has been reluctant to issue design guidelines that could be interpreted as exhaustive, or the entire answer, when they might have been written only as a start to encourage further development of evidence-based design principles.

When Has Enough Evidence Accumulated…

… to produce a guideline or a standard? If at some point enough evidence accumulates to be convincing, then many would expect that checklists, guidelines, principles, standards, regulations, or building codes could be promulgated with some confidence. This, then, would mean that the evidence had led to a product. There are many excellent and obvious examples. Serious analysis of findings from fires has led to the promulgation of the Life Safety Code by the National Fire Protection Association (NFPA, 2009). Another example might be the way numerous unrelated studies led to the U.S. Green Building Council's (www.usgbc.org) adoption of a lengthy checklist of design recommendations for projects seeking Leadership in Energy and Environmental Design (LEED) certification. Most LEED checklist items are backed by solid research and references to standards set by government entities.

A checklist may be the lowest level of recommendation. I tend to think of guidelines as nonbinding recommendations, somewhat more extensive than a checklist, perhaps with annotations that justify each recommendation. The credibility of guidelines is in direct proportion to the credibility of the organization that promulgated them. Guidelines from the Joint Commission or the American Academy of Pediatrics might be highly credible. Guidelines from AARP magazine, on the other hand, might be superb but less credible to a professional audience. I see standards as voluntary recommendations that may or may not be compulsory, but created on the basis of careful research and testing. A standard, it would seem, carries more weight than a guideline. Building codes, of course, are regulations that have the force of law. Many regulatory codes refer to standards, thus making the standard into a de facto code or regulation.

If these assumptions are mostly correct, then it might be possible to recommend a design concept in the form of a checklist on the basis of strong case studies and several successful examples. A checklist simply suggests that one consider the adoption of a design concept; it is away to ensure that nothing is overlooked.

Guidelines probably should be developed on the basis of a stronger case. Those planning to promulgate guidelines should be clear and explicit about the question of sufficiency. How much evidence is sufficient to permit the development of a recommendation from an entity whose credibility is at stake? What would constitute a preponderance of evidence? Ulrich, Zimring, Quan, and Joseph (2004) indicate that in some cases there is sufficient evidence for decision makers to act, such as that supporting the design concept of private patient rooms based on safety issues. Guiding principles seem to be the province of a specific client or design firm, meaning that these principles were deliberately chosen to guide an identifiable body of work. The Planetree organization, for example, insists that all its facilities be designed around patient-centered principles (Frampton, Gilpin, & Charmel, 2003).

Standards must be based on specific testing to confirm performance, and this testing must be performed by an organization with the appropriate expertise and an independent position. Finally, codes and regulations must be adopted only when the evidence is deemed to be conclusive, and when the public safety requires legal protection.

What Sorts of Standards Are Most Flexible…

… and allow for innovation and variation? Many in the design profession advocate performance-based standards versus the more prevalent prescriptive standards. A prescriptive standard says something like: “Evidence shows that patients benefit from sunlight, views of nature, and exposure to the diurnal cycle; therefore the glass area in patient room windows shall be no less than 15 square feet.” Yes, the research is solid on these issues, but is the prescription correct? How big should the window be? Should it be different on the north and south faces? Should it be different in northern Canada and southern Florida? How many clients will choose a window larger than the minimum standard if it is likely to cost more?

A performance standard, on the other hand says something like: “Each patient room shall receive 100 foot candles of natural light at noon on a typical December 21st.” In this case, the north-facing windows may be quite different from the south-facing ones. A performance standard describes a measure of desired performance and the design team is given the flexibility to arrive at a result in any way it chooses. A critical care room could be described as having to accommodate a patient bed, several types of sophisticated portable equipment, a staff zone, and a place for family participation. It need not set a minimum or maximum square footage because the individual project team can decide how to supply what is needed. A small town community hospital may not own enough equipment to require a huge patient room, which might be necessary at an urban quaternary teaching hospital. In practice we have seen critical care patient rooms increase in size to accommodate evolving need, yet building codes and licensing requirements have not changed.

How Can We Reach Agreement…

… about the quality of evidence? Unless there is some agreement about the quality of different types of evidence, there cannot be agreement about what is reliable. If there are to be clear hierarchies of environmental evidence, as in medicine, what will be the standard for findings to be convincing? What is the difference between sufficient evidence, a preponderance of evidence, and conclusive evidence? What level of evidence is associated with best practice? The practitioners of healthcare design and their clients are able to turn to a growing body of evidence, including manuscripts that appear on these pages. I believe these questions cannot be answered until there is a consensus entity with sufficient credibility to generate a basis for agreement. It is possible that the Evidence-based Design Accreditation and Certification model offered by The Center for Health Design (www.healthdesign.org) will produce a pool of interested individuals who share a common credential derived from an exam. Such a group may eventually be able to address these questions.

The Quality of Our Decisions…

… ultimately, is what it's all about. Lehrer (2009) tells us that we need to carefully observe our decision making and use the full power of both our rational and emotional capabilities. He suggests we use our rational brain for the simpler or novel problems that require reason. The rational brain has difficulty confronting too many variables.

Designers may not be aware of the frequency with which they access their emotional brains, applying deeply held values to bolster their judgment in the face of complexity They are acutely aware of any infringement on their freedom to make design decisions; therefore they often resist imposed regulations. Because of this strong desire to preserve freedom to design, I don't think the community of healthcare design professionals is ready for rigid or restrictive prescriptive standards; we may never be. But we may have reached the time to embrace helpful recommendations, checklists, preliminary guidelines, and simple performance standards. My intuition tells me there may be many times when well-considered guidelines could improve the quality of healthcare design projects. It may be time for interested parties to explore the idea of guidelines. HERD would be interested in publishing an open dialogue about how guidelines might affect decisions in the field.