Design Principles
Krug's Self-Evidence Principle
A page should be self-evident — users shouldn't have to think to work out what it is or what to do.
Where it comes from
It's the central argument of Steve Krug's Don't Make Me Think, first published in 2000 and one of the most widely read books on web usability. Krug's whole thesis is captured in the title: every question a page forces a visitor to answer is a small tax on their goodwill.
Why it matters for your website
The moment a visitor has to think "what is this?", you've lost ground. Steve Krug's core principle is that web pages should be self-evident — obvious at a glance to any reasonable person. Anything that takes effort to decode is burning attention that should be going toward converting.
Krug's law is unforgiving because it's about effort, not intelligence. A page can be perfectly logical and still fail the test, if working out that logic takes the visitor any conscious thought at all. The standard isn't 'understandable' — it's 'understandable without trying'.
The questions that cost you are the small ones a visitor shouldn't have to ask: Where am I? What is this? Where do I start? Is that a button? Is this for me? Each one is a moment of friction, and on the web friction is measured in departures, not patience.
Wrong vs right
A homepage whose headline is a clever slogan that leaves visitors unsure what the company actually does.
A headline that states plainly what the product is and who it's for, so there's nothing to decode.
Navigation labelled with invented, branded terms that force the visitor to guess what's behind each one.
Plain, conventional labels that say exactly where each link leads.
A layout where it's unclear what's clickable, what's a heading, and where the eye should start.
Obvious hierarchy and clear signifiers, so the page explains itself at a glance.
Understanding Krug's Self-Evidence Principle
Krug's self-evidence principle holds that a web page should be obvious — understandable at a glance by any reasonable visitor, with no conscious effort required to work out what it is or what to do. The title of his book, Don't Make Me Think, is the whole rule: every moment a visitor has to stop and puzzle something out is a moment of friction you've imposed.
The bar is deliberately high. It's not enough for a page to be figure-out-able; the figuring out is itself the cost. A clever headline, an ambiguous icon, an unconventional label, an unclear starting point — each forces a small act of interpretation, and those small acts accumulate into the feeling that a site is hard work, which is the feeling that precedes leaving.
The practical discipline is to relentlessly remove questions. Aim for a page where a visitor never has to ask 'what is this?', 'where do I start?', or 'is that clickable?' — because every such question is attention spent on the interface instead of on your offer. It underpins satisficing, the cost of clicks, and above-the-fold clarity.
How Kweri checks it
Self-evidence is partly assessable and partly a human judgement. Kweri can flag some concrete obstacles to it — vague or branded navigation labels, headlines that don't state what the product is, unclear signifiers, missing hierarchy — that tend to make a visitor stop and think. But whether a page is truly obvious 'at a glance' to your particular audience is something only real people glancing at it can confirm. So Kweri surfaces the likely friction points and prompts the 'what would make someone pause here?' question, while the final test is a five-second look from a fresh pair of eyes.
FAQ
What is Krug's self-evidence principle?
It's Steve Krug's principle that a web page should be self-evident — obvious at a glance, requiring no conscious thought to understand what it is or what to do. It's the core idea of his book Don't Make Me Think.
What does 'don't make me think' mean?
It means designing so visitors never have to stop and work things out. Every question a page forces — what is this, where do I start, is that a button — is friction. The goal is a page that's understandable without effort.
How do I make a page self-evident?
State plainly what the product is and who it's for, use conventional and descriptive labels, make hierarchy and clickability obvious, and remove anything that requires interpretation. Test by asking what a first-time visitor might have to pause and figure out.
Is self-evidence the same as simplicity?
Related but not identical. A page can be simple yet still ambiguous, or detailed yet self-evident. Self-evidence is specifically about requiring no thought to understand — clarity of meaning, not just fewer elements.
Who wrote Don't Make Me Think?
Steve Krug, a usability consultant. First published in 2000, it's one of the most widely read and influential books on web usability and is where the self-evidence principle is most clearly articulated.
Related principles
Every extra element competes with the important ones — cut what doesn't earn its place.
Among solutions that achieve the same goal, the one with fewest elements, steps, or assumptions is preferable — complexity that doesn't earn its place should be cut.
Good design externalises the knowledge users need to act — it puts it in the world, not in their heads. A product that requires memorisation is a product that requires training.
Attribution & sources
Identified by Steve Krug (2000). Catalogued from Don't Make Me Think (Steve Krug).
The central principle of Krug's Don't Make Me Think; there's no single canonical web source.
See Krug's Self-Evidence Principle on your own site
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