Chapter 1: Jacob's Law
__outline
__genesis
__example
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Chapter 2 Fitts' Law
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__genesis
__example
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Chapter 3 Miller's Law
__outline
__genesis
__example
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Chapter 4 Hick's Law
__outline
__genesis
__example
__organize

Chapter 5: Postel's Law
__outline
__genesis
__example
__organize

Chapter 6: Peak-End Law
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__genesis
__example
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Chapter 7: Aesthetic Usability Effects
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__genesis
__example
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Chapter 8: The von Restorff Effect
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__genesis
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Chapter 9 Tesla's Law
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__genesis
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Chapter 10: Doherty Criticality
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__genesis
__example
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Chapter 11: Design Meets Psychology
__Awakening the importance of psychological laws
__Design Principles
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Chapter 12: With Power Comes Responsibility
__How Technology Shapes Behavior
__Why ethics are important
__Slow down and be careful

[Added in the revised and expanded edition]
The principles and concepts covered in this book are timeless and provide a solid foundation for designers of all levels of expertise.
To enhance the reader's experience, this revised and expanded edition includes additional information and includes these laws and concepts under the topics of "Psychological Concepts," "Design Techniques," and "Deep Learning."
We've also updated examples throughout the book, making it a solid, practical guide for designers looking to stay up-to-date on the latest trends and best practices in design.

[Main contents of this book]
■ How does psychology relate to new technologies like AI and spatial computing?
■ What are the most useful psychological laws for UX/UI designers?
■ How does each psychological law relate to UX heuristics?
■ How do predictive models such as Fitts' law, Jacobs' law, and Hick's law work?
■ What are the ethical implications of using psychology in design?
■ Let's put into practice a practical framework that effectively applies psychological principles to the design process!

[This book's target audience]
I recommend this book to anyone who wants to develop their design skills, learn more about the intersection of psychology and design, or wonder why people respond in certain ways to good design.
This book is intended for designers who want to gain a deeper understanding of psychology, its impact on design work, and the commonalities between psychology and design.
Whether you're a practicing or aspiring designer, this book will be helpful to anyone who wants to understand how human perception and mental processes impact the overall user experience.
Although this book focuses on digital design, as opposed to traditional mediums like graphic design or industrial design, the information contained here is broadly applicable to anyone responsible for creating user experiences.


[Author's Note]
The motivation for writing this book was the hope that it would help more designers approach the complex laws of psychology more easily.
This is especially true for designers who don't have a background in psychology or behavioral science.
In an era where design's role within organizations is more influential than ever, the intersection of psychology and user experience (UX) design will become increasingly relevant.
As interest in design grows, opinions differ on what additional skills designers should acquire to enhance their value and capabilities.
Should I learn coding or writing? Or should I build my business knowledge? All three can be valuable, depending on the project, team, or industry you're involved in.
However, a basic knowledge of psychology is a virtue that all designers should have.

Every human being has a "blueprint" for how they perceive and process the world around them, and studying psychology can help us decipher this blueprint.
Designers can use this knowledge to create more intuitive and human-centered products and experiences.
By leveraging the key principles of psychology, we can create designs that resonate with humans without forcing users to adapt to the design of our products or experiences.
This is the foundation of human-centered design and the basis of this book.


But it can be difficult to know where to start.
Which laws of psychology are useful? Which of these laws are applicable in practice? While countless laws and theories could answer this question, I've selected a few that are particularly useful and widely applicable.
This book explores these concepts and presents some examples of how they can be effectively applied to the products and experiences we interact with every day.

[Translator's Note]
I have several banking apps installed on my smartphone.
Among them, the most used app is definitely Kakao Bank.
The reason is simple.
Because it is easier to use than other apps.
From signing up to transferring, no public certificate is required, and account transfers are as easy as sending a message.
Perhaps because everyone else feels the same way, the bank, which has pledged to introduce "innovative, user-centric technology," continues to see solid growth, surpassing 23 million subscribers as of the fourth quarter of 2023.

The term 'User Experience' was coined by Donald Norman while working at Apple in 1993.
Norman later founded the Nielsen Norman Group with Jacob Nielsen, who created 'Jacob's Law', which is first introduced in this book.
Norman is a renowned cognitive psychologist with a PhD in psychology and an engineering degree in electrical engineering.
It is no exaggeration to say that user experience design has focused on users, that is, humans, from the beginning, and has grown alongside psychology to form numerous branches.


But the problem is that everyone now knows that user experience matters.
Rather, it is now nothing more than a cliché to just keep talking vaguely about improving the user experience without any solid evidence.
This book starts from that very problem.
The author of this book, John Yablonski, says he once came close to doing something like that.
The idea was to provide stakeholders with a basis for decision-making before quantitative and qualitative data were available to justify design decisions on the assigned project.
For example, we all know that the faster a website responds, the better its usability.
However, if you simply give an arbitrary value without any basis in answering the question, "How fast should it be? How slow is acceptable?", you are likely to encounter opposition.

In this situation, the answer that saved Yablonsky was psychology.
He said that he was able to persuade stakeholders much more easily by using psychology papers as empirical evidence.
And in the process, I realized that there was a serious lack of psychological materials that could directly help designers, so I set out to create such materials myself.
So, the author's website, which is the origin of this book (Laws of
UX (https://lawsofux.com) was born.
And this book is the result of selecting and including 10 of the many psychological laws that have been developed and that are particularly useful and widely applicable.
In the case mentioned above, the 'Doherty Criticality' in Chapter 10 will provide the answer.

Chapters 1 through 10 each introduce one psychological law, focusing on its definition, origin, and abundant examples.
Among the psychological concepts or design techniques that inevitably appear in the meantime, I have provided additional explanations in separate spaces for items that I thought required a more detailed explanation.
In particular, this revised and expanded edition has been carefully updated with the latest versions of all the cases introduced in the first edition and has shown kindness by introducing the historical context of the intersection of design and psychology.

Additionally, at the beginning of each chapter, there is a poster that concisely expresses the psychological laws covered in that chapter.
A total of 20 posters of psychological laws compiled by the author, including the 10 posters included in this book, are also available for free download from the Laws of UX website.
This is a thoughtful gift designed by the author himself, hoping to help you recall and internalize the psychological laws learned in this book.

As the author states in the preface, this book is designed as an introductory text, and maintains a practical attitude and concise tone throughout. If the title piques your curiosity and you pick it up, even those not directly involved in UX design will find it helpful in broadening their common sense.
However, after introducing the laws, Chapters 11 and 12 systematically guide readers through how to embody and immediately apply the theoretical knowledge in practice, as well as how to use these laws responsibly rather than abusing them. Therefore, the readers who will benefit the most from this book are UX designers.

Knowing and understanding are different.
Rather than simply acquiring and applying various user experience patterns as knowledge, understanding and applying the underlying psychological laws will lead to a much more persuasive interface.
I hope that readers of this book, who have gained a better understanding of the "blueprint" of humanity thanks to the author's efforts, will see the birth of more human-centered designs.