Post-occupancy surveys and/or interviews are a common tool used in architecture to evaluate the success of buildings. They can be very useful and should be implemented as long as architects do not expect or claim too much from them. Much has been said of their benefits, but it is concerning to see some architects present them as some kind of scientific proof of a design’s success or failure. Although I am a strong advocate for post-occupancy surveys, I think a little pushback is necessary. A brief review of their methodological weaknesses should make any architect pause before claiming a survey has vindicated their ideas.
First, obtaining a reasonably random sample of people is difficult in any survey. In the case of a single building, like a school, a survey is that much more vulnerable to selection bias. Unless the staff and students were randomly assigned to the school the survey will inevitably be biased. This means the post-occupancy surveys inadvertently bias the results toward certain socioeconomic levels. It will not be representative of the population at large. This makes it difficult to tell where the socioeconomic effects end and the architectural effects begin.
Even if a building is a representative sample of the general population, the users who feel more strongly about the building can influence the survey. They will be more eager to complete the survey and give feedback. These squeaky wheels will unintentionally or intentionally create a selection bias that favors their interests. Those less interested in the subject are less likely to fill out the survey. Subsequently, the survey might only reflect an extreme view that few other occupants agree with.
