Mismatch by Kat Holmes Book Summary

Mismatch, How Inclusion Shapes Design by Kat Holmes


Kat Holmes takes an underserved component of the diversity and inclusion genre and does it great justice in this slim volume. Though often overlooked, inclusive design has the potential to change the world. As Holmes points out, it already has through inventions such as touchscreens and email – originally designed to aid a small minority of disabled users – that now serve as standard tools for all. Nevertheless, most design continues to exclude, intentionally or not. Those involved in creating products will find a compelling and urgent case for inclusive design and practical tips for getting there.


  • Conventional design yields tools and technologies that many cannot use easily or at all.
  • Design that excludes harms people psychologically and physically.
  • Make inclusivity a hallmark of professionalism.
  • You cannot design anything that fits every potential user, but you should try.
  • Build for inclusion from the start of the product development cycle. 
  • Don’t focus on one aspect of exclusion, such as gender. Design holistically, to include as many people as possible.
  • Don’t make users adapt to your designs; adapt your designs to users.
  • When your design excludes, assume you missed the mark.
  • As a leader, build inclusion into your long-term design plans and give employees ways to contribute.
  • Intentionally inclusive design addresses pressing global challenges.
mismatch book cover

Mismatch Book Summary

Conventional design yields tools and technologies that many cannot use easily or at all.

Countless technologies and consumer products – from phones and computers to cars and elevators – pervade every aspect of daily life. Millions – sometimes billions – of people from every imaginable demographic use these devices, but their creators almost always designed them to suit a so-called normal or average user. No such person actually exists.

“Designing for inclusion starts with recognizing exclusion.”

These designs suit almost no one well and their designers leave a fortune on the table by excluding millions or billions of potential customers. Products for the mythical norm create a mismatch between the design of tools and technologies and the optimal ways people should interact with them.

Design that excludes harms people psychologically and physically.

When people encounter common instruments – whether the size of the text on a set of instructions, a touchscreen checkout terminal or a smartphone – whose design excludes them, they may adapt, but will feel excluded. Adapt your designs to users, rather than forcing people to adapt to them.

“Inclusive design doesn’t mean you’re designing one thing for all people. You’re designing a diversity of ways to participate so that everyone has a sense of belonging.”

Those hoping to design inclusive products must acknowledge that their culture and ways of doing things exclude others. Social rejection undermines people’s sense of belonging, impairing them psychologically and emotionally, and, often, causing physical pain and damaging their well-being. As a designer and/or leader, stay aware that you in fact choose who participates and contributes.

Make inclusivity a hallmark of professionalism.

Before you start designing, consider who your designs might exclude. Acknowledge that this means almost everyone on the planet – at least at some point in time. For example, the World Bank estimates that at one time or another, 6.4 billion people – the majority of the world’s population – suffer from a disability. This includes virtually everyone who survives to old age. In other words, inclusive design benefits you and almost everyone you care about.

Listen to a diverse group of people, including customers, who might use your products, and to experts and others from whom you might gain valuable insights. The excluded usually possess the best knowledge and insight about how to include them, so learn from them. Don’t embrace inclusive design out of sympathy for the excluded. This makes inclusiveness a low priority – one your firm might abandon at the first inconvenience. Make inclusivity a hallmark of professionalism – a prerequisite to building a reputation as a great designer, teacher, engineer or leader.

“There are many challenges that stand in the way of inclusion, the sneakiest of which are sympathy and pity.”

Ambiguity and uncertainty accompany inclusive design. You can’t always include everyone, at least in your initial efforts. Accessible public restrooms, for example, may accommodate wheelchair users, but the height of counters and design of taps and dispensers may continue to present challenges. Designers have not yet figured out how to accommodate everyone; but you must keep striving for that goal.

You cannot design anything that fits every potential user, but you should try.

Avoid excluding people by accident. Break from the status quo. Make the decision to design for intentional, broader inclusion because you can; because, with practice, you’ll get better at it; because inclusive design can make an enormous positive difference in the world; and because it can confer tremendous competitive advantage in gaining new customers, sparking innovation and avoiding the need to retrofit solutions. 

“There is no single answer that suits everyone. Accessible solutions are always, inevitably, accessible to some but not all people.”

Know that when you design to include a subset of the previously excluded, your design often spreads to far larger peripheral groups and, sometimes, virtually everyone. For example, while designers invented closed captioning for the deaf, it now serves countless others, whether in noisy airports, places that demand quiet, those who hear with difficulty or kids learning to read.

Build for inclusion from the start of the product development cycle. 

Work collaboratively across departments and contributors to ensure inclusion across each element of your product – failure in one design aspect can render other inclusive elements irrelevant. Inclusive design never ends, as new challenges and ideas continually emerge. With effort and intent, you can always improve.

Avoid designing for the mythical average person or against standard personas meant to represent typical users. Crucially, build in flexibility so different users can interact in ways that best suit them. Use personas to think through a design that may at first help a person with a clear disability and could eventually accommodate others. For example, a design that works for a person with one arm might also aid someone with a broken arm or even a parent carrying a baby. In this way, you can design for the few with results that might serve billions.

Observe how people interact with and use your products. Combine big data about people in the aggregate with “thick data” that adds nuance and context, especially concerning those who most mismatch with your design. Let big data direct you broadly in your solutions and rely on thick data for specifics.

Don’t focus on one aspect of exclusion, such as gender. Design holistically, to include as many people as possible.

Systemic exclusion dates as far back in history as you care to look. More recently, for example, it prevented Black people from living in better communities and accessing urban amenities and/or destroyed thriving communities for racist reasons. Moreover, it effectively excluded people from various professions or positions of leadership. Society bakes exclusion into its basic functions. This cycle eventually harms everyone and must end.

In experiments in which schoolchildren must allow every kid to join their group who wants to – no exclusion allowed – the kids adapted quickly, made new friends and invented more creative games. Likewise, in product design, potential correlates with inclusivity: The more users the better. Designs that include people gain those people’s ideas and contributions.

“It is most effective, and generally less expensive, to prioritize inclusion as early as possible and build inclusive solutions from the ground up.”

Don’t focus on one aspect of exclusion, such as gender, or age, for example. Attempts to build a car for women – the Dodge La Femme – failed miserably in the 1950s, as did thinner pens for “the lady’s small hands.”

Design holistically, to include as many people as possible. Break the exclusionary default in design by acknowledging that default and taking responsibility for changing it. Think through the “why” of your product. In most cases, one of the reasons you create a product is to attract the most users possible. This makes inclusion part of your “why.” Use this logic to bring senior leaders on board from the start.

Don’t make users adapt to your designs; adapt your designs to users.

Over the decades, video game controllers, for example, have grown heavier and more complex. They require two hands and a good deal of dexterity. They basically scream: “I was built for some but not others.”

Most video games assume users will play one specific way. Others, like World of Warcraft offer numerous ways to participate, some of which don’t require speed or dexterity. Consequently, Warcraft attracts people with disabilities who might set up shops in the virtual world or participate in ways that suit their unique abilities.

You cannot overemphasize this lesson of inclusive design: Make your products flexible. Consider too, that as more people with disabilities have become video game designers over the past several years, games have become more inclusive. As a result, the industry – and its audience – has changed and grown.

“Disability is commonly misunderstood as applying to only a marginal percentage of the human population. This is simply untrue.”

Everyone can pull from the lessons of inclusive and flexible video game design. Review your hiring process to accommodate those who have difficulty completing long, online applications or responding extemporaneously in high stress interviews, for example. Assemble diverse teams of designers based on multiple factors, including demographics and abilities. Designers tend to build to their abilities; having diverse colleagues aids in creating alternative means of participation for diverse users.

When your design excludes, assume you missed the mark.

Though the United States and international laws have required inclusive design in computer-based products for the past half-century, adoption lags, due, in part, to poor integration of inclusive design in education, complex legalese and substandard tools to test solutions for accessibility. Ideally, designers will come to view access barriers not as outlying events, but as “mismatched interactions.”

This new, evolved mind-set removes stigma and places accountability for design where it belongs – on the designer, not the user. Laws and regulations aside, inclusive designers look for these mismatches and attempt to resolve them. They actively seek the input of those potentially affected by their designs. They analyze the various ways people interact with their products and build the results of that analysis into new product iterations.

“Designing for, not with, people can lead to exclusion.”

Design with people’s emotions in mind. For example, consider how they did things before and – to minimize disruption – retain familiar elements when designing improved methodologies. Create options for learning how to use new tools for those who learn through experimentation versus others, for example, who prefer instructions. Make sure design updates and new tools work with assistive devices that various users depend upon. Again, seek out and consider input from as wide a range of potential users as possible.

As a leader, build inclusion into your long-term design plans and give employees ways to contribute.

Audit the exclusionary practices in force presently, announce changes and keep your word. Recognize and reward those whose behaviors and actions further your inclusive design goals. Encourage empathy and the uniqueness of every individual, so your designs can serve everyone.

When you design to include marginalized people, your inventions often assist many others. Such inventions include, for example, speech recognition and voice controls, which developers created for those who could not use keyboards and computer mice. Now, virtually everyone in advanced economies talks to their cars, computers or other devices. Consider how your inclusive design might appeal to a broader set of users to build a compelling business case for inclusive design.

Designers created the typewriter to enable a blind countess to write letters. Vint Cerf invented email because he and his wife suffered hearing loss and needed a way to communicate. These inventions achieved near universal adoption, generating billions of users and customers. Seek out and share similar stories within your own firm and/or industry.

Intentionally inclusive design addresses pressing global challenges.

Volatility and uncertainty characterize the modern world. Growth depends on leveraging the perspectives and talents of all people. 

“There is one reason for inclusion that transcends all other justifications: uncertainty.”

No one knows how AI, machine learning and other technologies will evolve, but they might reduce humans to algorithmic predictions. Only through intentional design, starting now, might AI consider thick data and potentially unlock the ability to cater to every individual infinitely and uniquely – eliminating mismatches entirely.

About the Author

Kat Holmes

One of Fast Company’s Most Creative People in Business, Kat Holmes founded and leads Mismatch.design, where she advises firms on inclusive design.

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