An open-access textbook of usability — the science of designing things that people can actually use. From the cognitive psychology of perception, attention and memory, through the laws and heuristics of interface design, to the methods of usability testing, evaluation, and accessibility. For designers, software engineers, clinicians, researchers, and anyone who builds things that other humans must operate.
About the author
Dr Chris Paton is an AI researcher at the University of Auckland, New Zealand. He received his DPhil (PhD) in Usability of Digital Health Technologies from the University of Oxford, UK.
How to use this book
This is an open-access online textbook. Use the navigation above to browse chapters, look up terms in the glossary, or return to the home page. The textbook can be read in order or used as a reference.
Copyright and licence
© 2026 Dr Chris Paton. All rights reserved. Content may be quoted with attribution.