10 UX laws that make or break an experience
Why laws?
UX laws are not rules you must obey. They are short names for how people already behave, which makes them useful for explaining a design decision to a team in one sentence. I wrote this guide in Arabic because most material on the topic is in English.
1. Hick’s law
The rule: The more choices, the longer it takes to decide.
Why it matters: A long list of options slows people down and makes them hesitate.
Example: A store with thousands of products stays fast to browse with a few top categories plus filters. Seen in: Amazon (filters)
2. Fitts’s law
The rule: The time to reach a target depends on its size and distance.
Why it matters: Large, clear buttons close to where the thumb already is are faster to hit.
Example: A “Next” button in the bottom corner of a phone screen, within thumb reach. Seen in: YouTube
3. Jakob’s law
The rule: People expect your product to work like the ones they already use.
Why it matters: Breaking expectations causes confusion; familiarity creates comfort.
Example: Online stores put the cart at the top corner. Move it somewhere odd and people won’t find it. Seen in: Amazon
4. Law of proximity
The rule: Things placed close together are understood as related.
Why it matters: People group nearby elements even without borders or lines.
Example: Text directly under a button is read as describing that button. Seen in: LinkedIn
5. Law of similarity
The rule: Things that look alike are seen as one group.
Why it matters: Buttons with the same style are assumed to do similar things.
Example: Grey buttons for secondary actions, green for “continue” or “confirm”. Seen in: iOS Settings
6. Miller’s law
The rule: People hold about 7 ± 2 items in short-term memory.
Why it matters: Show fifteen pieces of information at once and most will be forgotten.
Example: A long, unsorted task list is hard to remember; grouped tasks are easier. Seen in: Dropbox
7. Tesler’s law
The rule: Every system has complexity that can’t be removed, only moved.
Why it matters: Good design doesn’t delete complexity; it hides it or spreads it cleverly.
Example: Tax forms are complex, but tax software walks you through them one step at a time. Seen in: TurboTax
8. Peak-end rule
The rule: People judge an experience by its most intense moment and its end.
Why it matters: A delightful ending can outweigh small problems along the way.
Example: A friendly congratulation after sign-up leaves a positive memory. Seen in: Duolingo
9. Pareto principle (80/20)
The rule: About 80% of results come from 20% of the effort.
Why it matters: Most people use a handful of features out of many.
Example: Most time on Instagram is scrolling, so the interface is built around it. Seen in: Instagram
10. Serial position effect
The rule: People remember the first and last items best.
Why it matters: Start and end with what matters most.
Example: Netflix puts the most important rows first and last. Seen in: Netflix
How I use them
In my case studies you will see these names next to design decisions: Hick’s law behind a home screen with only two tasks, Fitts’s law behind a large booking button, proximity behind grouped stats. They are a shared language, not a checklist.
Sources and a correction
Miller’s 7 ± 2 is the famous number, but later research puts working memory nearer four chunks (Cowan, 2001). I treat it as a reminder to group and chunk information, not as a number to design to.
- Hick, W. E. (1952). On the rate of gain of information. Quarterly Journal of Experimental Psychology, 4(1).
- Fitts, P. M. (1954). The information capacity of the human motor system in controlling the amplitude of movement. Journal of Experimental Psychology, 47(6).
- Nielsen, J. (2000). End of Web Design. Nielsen Norman Group (the source of Jakob’s law).
- Wertheimer, M. (1923). Untersuchungen zur Lehre von der Gestalt II. Psychologische Forschung, 4 (proximity and similarity).
- Miller, G. A. (1956). The magical number seven, plus or minus two. Psychological Review, 63(2).
- Cowan, N. (2001). The magical number 4 in short-term memory. Behavioral and Brain Sciences, 24(1).
- Kahneman, D., Fredrickson, B. L., Schreiber, C. A. & Redelmeier, D. A. (1993). When more pain is preferred to less: adding a better end. Psychological Science, 4(6).
- Murdock, B. B. (1962). The serial position effect of free recall. Journal of Experimental Psychology, 64(5).
- Juran, J. M. (1951). Quality Control Handbook. McGraw-Hill (the Pareto principle).
- Yablonski, J. (2020). Laws of UX. O’Reilly Media (Tesler’s law and a practical overview of all ten).
