Laws of UX

A curated collection, not a new theory. Yablonski gathers known findings from psychology and HCI and restates each as a design rule. He launched the site in mid-January 2018 "with 10 laws".

Laws about movement and choice. Fitts’s Law: the time to hit a target depends on its size and distance. Hick’s Law: decision time grows with the number of choices.

Laws about memory and attention. Miller’s Law, the Serial Position Effect, the Von Restorff Effect, the Zeigarnik Effect and cognitive load describe what users can hold in mind and what stands out.

Laws about expectations. Jakob’s Law: users expect your site to work like the sites they already know. The Aesthetic-Usability Effect: users judge attractive designs as easier to use.

Laws about experience over time. The Peak-End Rule, the Goal-Gradient Effect and the Doherty Threshold concern how users remember an experience, how they speed up near a goal, and how fast a system must respond.

Laws about complexity. Tesler’s Law: every system has complexity that cannot be removed, only moved. Postel’s Law: be liberal in what you accept, conservative in what you send.

Grouping laws from Gestalt psychology. The collection includes the Law of Proximity and the Law of Common Region.

Reviewing a form or screen when the findings should cite a mechanism: target size, number of choices, memory load

Arguing a design decision with stakeholders in terms of known effects

Planning response times, onboarding steps and progress indicators

Asking a model to review a UI: with the anchor, it cites Fitts’s and Hick’s Law as a rule and, on the stronger tiers, ten or more laws

Taking them for laws of nature. The collection mixes models, effects and heuristics of very different strength.

Reading Miller’s Law as a cap on menu items. It concerns short-term memory, not how many entries a navigation may have.

Applying one law in isolation. The laws interact and can pull in different directions; one law alone rarely settles a design question.

Expecting the baseline to name them. In our prior test on 2026-10-28, no baseline review of a signup form cited a single law. With "Laws of UX", six of six runs cited Fitts’s and Hick’s Law, five of six Miller’s Law; Sonnet and Opus cited ten to twelve laws per answer.

Not laws, and an arbitrary selection. Marcin Wichary argues in "Book review: Laws of UX (2nd ed.)" (Unsung blog) that the "laws" are not laws in a scientific sense and that the choice of entries is arbitrary: "the book doesn’t fully understand how design works."

An outdated reading of Miller. D. Ben Woods notes in his UXmatters review (23 November 2020) that the Miller’s Law chapter still relies on the old figure of seven plus or minus two.