Holmes cites an example where the US Air Force attempted to create a fighter jet that would fit the average body, taking thousands of measurements from pilots to determine the exact best fit. The problem with designing for average - ethics aside - is it doesn’t actually work. It formed the body mass index (BMI) measure and fed into dangerous ideologies such as eugenics. This idea became pervasive and has influenced other fields of study. Diversity and variations in human beings were treated as degrees of error from perfection. From this comparison, one could calculate the innate degree of “abnormality” of an individual person. In its pages, he held that individual people should be measured against that perfect average. “When he published his Treatise on Man it was a revolutionary work.

What emerged was a bell curve, showing the average in the centre, with those data points plotted off to the side being treated as deviations from the norm. Holmes discusses how society’s understanding of “normal” has been heavily influenced by a 19th-century mathematician, Adolphe Quetelet.* Attempting to better understand human society, Quetelet gathered data on humans (physical characteristics, behaviours, ‘moral categories’) and plotted them all on a graph. But to suggest that there is even such a thing as a “normal” human is a huge oversimplification. We can then come back to look at the edge cases later if there’s time. The prevailing narrative has been that we should design for the majority of (read: normal) users. There is no such thing as a “normal” human being. The danger of designing for the average user Most importantly, this means including and learning from people with a range of perspectives.”Ĭrucially, this means including contributions from people from communities that are typically excluded. “A methodology that enables and draws on the full range of human diversity.

You’re designing a diversity of ways to participate so that everyone has a sense of belonging.”Ī key factor of inclusive design is process - how did you get to your outcome? Were your processes inclusive? Another definition she puts forward, emphasises this process element: “Inclusive design doesn’t mean you’re designing one thing for all people. One definition that Holmes cites comes from inclusive design leader Susan Goltsman: Holmes focuses on the way in which design can exclude, and believes that the mission of inclusive design is to counteract those exclusions - or “mismatches” - between service and user. There is no single definition for “inclusive design” and it can be hard to capture all of the nuances in a fixed definition.

Mismatch by Kat Holmes