How to write a UX design brief without acting like a kid in a sweet shop

Too often a brief for a website redesign reads like a shopping list for a kid in a sweet shop– every feature you’ve ever thought of is included, from search and complex filtering to interactive maps and videos.



Image credit: Copyright Lewis Clarke and licensed for reuse under this Creative Commons Licence

What’s wrong with the “kid in a sweet shop” approach?

Imagine if you actually did your shopping like that. You’d get home and find you have nothing to actually make a meal with. Just a lot of stuff that you’ll probably gorge on and then feel sick after eating. Compare this with a properly planned shopping list where you’ve bought the necessary ingredients for a few meals, stocked up on basics and treated yourself to a couple of luxuries. Money well spent!

It may be stretching the analogy somewhat, but if you have an unplanned and lengthy shopping list of features for your website, you risk ending up with something that’s expensive to build and not fit for purpose.

Features are not going to win customers. It’s about the experience. Your website needs to be based on core objectives and user needs – it should do just a few things and do them well.

So, how do you do this? How do you work out what those essential features are? How do you meet your key objectives? How do you find out what your customers want?

The Kano Model

Created in Japan in the 1980s, the Kano model provides a systematic way of evaluating features to determine where to invest. Features are assessed against the satisfaction that they will bring to customers (shown on the vertical axis and ranging from extreme frustration to extreme delight) and the amount that is invested in them (shown on the horizontal axis from low to high).


Image credit: Kano model taken from


Features are classified into three main categories:

• Basic Expectations are those features that will cause extreme frustration if they are missing, but that only ever achieve a neutral level of customer satisfaction no matter how much you invest. These are the basic “must-have” features such as making calls on a phone or having brakes on a car;

• Performance Payoff features are those where increasing investment leads to increasing returns in terms of customer satisfaction. These are things like the speed of a broadband service or the fuel efficiency of a car;

• Excitement Generators are features which are genuinely unexpected and will cause extremely high levels of customer satisfaction, sometimes for relatively little investment. These are the features that will help you to stand out and are the equivalent of the little treat on your shopping list. Anything from a little thing like freebies included in your online order to a step change like the unlimited storage in gmail.

It is worth noting that over time, features which were originally Excitement Generators will be copied and will become the norm. As this happens, they will change to Performance Payoff features and eventually become Basic Expectations. Taking a photo with your phone was once exciting, now it’s a standard feature.

Note also that it’s not all about customer delight. If you haven’t provided the basics your product will fail no matter how many exciting features you’ve included. In an in-depth study of customer service (both on and offline), Harvard Business review reported that “delighting customers doesn’t build loyalty; reducing their effort—the work they must do to get their problem solved—does”, reflecting the importance of getting the basics right.

Finding the Balance

So, how do you use the Kano model to ensure that you get the right shopping list of features? What are the basics that you must have? How much should you invest in Performance Payoff features? What are the inexpensive features that will delight customers?

User research is obviously the best way to evaluate your possible feature list – selecting the right research method is key. This could be a case of simply asking people to evaluate features or to answer questions such as how they’d feel if a feature was missing. Straightforward research like this can be conducted through in-depth interviews, guerrilla research or even an online survey depending on requirements. More complex features could be investigated by creating and testing a prototype to help potential customers understand exactly what you’re proposing.

So, don’t just guess and grab at every available feature like a kid in a sweet shop would - create a shopping list of features based on what your customers expect, want and need. Take the time to evaluate them carefully, carrying out some user research to help you determine where best to invest your time and money. Your effort will pay off – you’ll identify a manageable set of features that is achievable within your budget and that will deliver customer satisfaction. Then you’ll be well on your way to writing a great UX design brief!

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