Peak-end Rule applies in UX
(October 16, 2013)

If you have or work with kids you might be aware of a version of the Peak-end rule. Make sure that the kid stops some activity while they’re still having fun. Don’t wait until they get bored, tired or are having problems before you end the activity. This rule applies to all kinds of UX situations and is a great UX technique to employ in your site, presentation or application design.

Simply speaking the rule is:

 People judge experiences largely based on how they were at their peak and at their end…and this occurs regardless of valency (whether pleasant or unpleasant).”

The experiments this rule is based on looked at how the experience of pleasure or pain is largely erased by the memory of the pleasure of pain. We don’t remember pleasure or pain by how long it lasts, rather, it’s a combination of the feeling of great intensity – the PEAK – and the impression left by the final moments of the experience – the END – and whether the end is better or worse than the preceding moments. That is to say we remember events by their PEAK and their END and the average of the two.


Progress bar speed: Fastest progress at the end is perceived as faster overall.

While aiming for a great experience site- or app-wide is a worthy goal, we all understand that anything has peaks and valleys. The thing is that planning Peaks and the End point is key to success and certainly a quick win when looking to make site improvements.

Let’s start with the End

Success and logout messages: These are often the end of a user experience. Making them more memorable and pleasurable, and certainly removing any pain is where good UX comes in.

If we assume that the user has had to do some “work” to complete their task (order fulfillment, registration) to end up at a Success message, we can understand where some reward could have a payoff. Immediate positive feedback, letting the user know that things worked as they had intended is the first key.


Making it fun – ludic – with amusing copy or graphics even if they are on a more serious site, can provide that end bias that we’re looking for.

Empowering and a sense of accomplishment are also easy to convey here. Let them feel that they can check this thing off a to do list; that they did it in less time than the average user.

Rewards pure and simple like offering bonus points or discounts for future site use. These rewards should have a point and actually be worth something to the user.

And of course there’s always the social proof aspect. Many people like sharing even seemingly meaningless accomplishments with friends and family. Maybe let users know that others have completed the process and or that their friends have also been there.

These are the easy wins. Planning the peaks takes a little more work and an in-depth understanding of users.

Planning Peak Performance

Just as an athlete plans for a competition, planning a cycle we need to look for the moment when a user is most likely to feel pleasure or pain with a process.

Taking care to break tasks into small chunks rather than one mountainous one, is one way to send users to the edge. Letting users know that it’s almost over can be a big help. Progress bars that actually move at a reasonable pace even for the slowest user, also work.

When it comes to planning out user experience a big part of what we look at is telling the story. All good stories have their high points. It’s important to remember that by definition, not everything can be a peak. Identify the key moment in your story, in your users’ potential interaction on your site and prime it with positive moments and sensory appeal.

At these key moments, the more senses that you can touch, the greater the likely hood for a peak memory. More senses means that you have a greater possibility to touch emotions. Video touches multiple senses. Audio feedback to actions and strong images are all keys. Keeping copy up beat and positive is relatively easy to accomplish.

Making someone smile is not always easy, but it generally implies a positive moment. Don’t be afraid to offer humor or a surprise. Google often refers to Easter Eggs in their applications. There are many sites that offer lists of Google Easter Eggs you should check them out. Google it. Oh, and while you’re there, search the word “tilt” and enjoy your search results displayed on… you guessed it, a tilt!


It’s rare to be able to make an entire experience pleasurable, but while the overall experience might not be top notch, you can win the UX battle with a high positive peak or a great finish. And as with the kids example at the beginning, I’ll leave this article as is. ‘Cause sometimes you should quit while you’re ahead.

If you want to know more about this topic, you can look up Daniel Kahneman hypothesises in Thinking, Fast And Slow: the peak-end rule. You may also enjoy his TEDtalk.

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