What Are Heuristics? Simon to Nielsen

What Are Heuristics? Simon to Nielsen

In the broadest sense, a heuristic is an informal rule that assists in decision-making. The academic study of heuristics as a branch of Cognitive Psychology was initiated by Herbert A. Simon. In his 1947 book “Administrative Behaviour” he coined the phrase “satisficing”- this theory posited that human beings make judgements about solutions that are good enough for their need rather than perfect. Subsequently there has been much academic debate about whether heuristics lead to better or worse decision-making, with Tversky and Kahneman criticising heuristics as open to being skewed by cognitive biases, and Gigernezer and his team finding that applying heuristics can lead to better outcomes with less effort.

Some CRO/UX agencies and consultancies (Binary Bear included) use heuristics as part of their site review process- usually to initiate ideas for ongoing AB Testing. Heuristics in this sense means rules of thumb that are applied to web design by experienced evaluators. These rules of thumb are indications that a design may be sub-optimal in some way. Common applications could be that a site’s value proposition isn’t clear, the navigation is difficult to use, or that the call to action isn’t persuasive enough.

It’s important to state that a heuristic review should only be the starting point of a site evaluation. Most findings from heuristics also need to be validated by quantitative evidence (e.g. from web analytics) or supported by qualitative findings (e.g. user testing).

In this series we’ll evaluate some well-known heuristic models and share one of own.

The best known (and longest lived) application of heuristic principles to web design is the 10-point plan written by Jakob Nielsen in 1994. Can something written 25 years ago tell us anything about modern web design? Let’s take a look, with a 2019 head on, at the first five of these heuristic rules.

#1: Visibility of system status

The system should always keep users informed about what is going on, through appropriate feedback within reasonable time.

Does this still apply? Arguably, yes. Effective e-Commerce sites often have basket icons with basket values or numbers of item in basket permanent visible (think Amazon). Logged in or logged out status is also often indicated above the top navigation. And in the example from We Transfer below, the counter indicates how long the file will take to upload. So heuristic #1 gets a thumbs up from us.


  • Do you make users aware of time constraints for offers?
  • Do you indicate value or quantity in basket throughout the site?
  • Do you use progress bars on checkout/sign up pages?

#2: Match between system and the real world

The system should speak the users’ language, with words, phrases and concepts familiar to the user, rather than system-oriented terms. Follow real-world conventions, making information appear in a natural and logical order.

In earlier days of web design, failed user states prompted system error codes (anyone remember uncustomised 404 error pages?) Mostly, brands now present custom 404s when old pages have been removed, like the snazzy on-brand version by Lego shown below.

Another evolution in content generation, this time from the early days of SEO, saw spammy keyword stuffing, where body content used excessive repetition to fish for keyword visibility:

Thankfully, as Google’s spam team closed-down this avenue long ago, few SEOs write copy like this anymore. There is still one legacy though- some copywriters overuse of technical detail and jargon- this often affects B2B sites.  Running your body copy through a readability tool like Readable.com will help give you an indication of the ease of reading of your proposition text. So, in summary- yes, heuristic #2 is still a thing.


  • Are you using the language your customers would? Read your copy again and check where jargon could be replaced with plain English.
  • Do your filters reflect the choices required by your customers (e.g. sorting by price, hotel with a pool etc)?
  • How do your customers group your product categories? Find out with card sorting exercises and use this categorisation, not one provided by your marketing team.
  • Do your choices of images and photography reflect the product or service on offer, or does it require context?

#3: User control and freedom

Users often choose system functions by mistake and will need a clearly marked “emergency exit” to leave the unwanted state without having to go through an extended dialogue. Support undo and redo.

Does this still apply? From watching many thousands of user recordings, we can see users routinely clicking the back button on the browser to return to an earlier page, but what of the on-page design? Responsive design and the rise of mobile has arguably contributed to the reduction in the use of breadcrumbs to help users orientate themselves (partially compensated for by sticky navigation). There are plenty of examples of users being manipulated by bad design which prove that user control and freedom is still important.

In the example below, Microsoft (yes, the very same) abused a design convention (the ‘x’ to close a dialogue box) to trick the user into upgrading to Windows 10.

Another sneaky application of this convention with dialogue boxes or modal windows is the floating “x” which is difficult to see against the background of the page. Ultimately, employing dark patterns such as these damages the brand, contributing to the impression that Nielsen’s third heuristic rule still has validity.


  • Do you make it harder than necessary for a user to close down an interface or take a sideways step in their journey?
  • Are your cross sells or upsells always timely and appropriate?
  • Do you use abandonment as an opportunity to find out more about your users i.e. by running exit surveys or incentivising newsletter sign ups?

#4: Consistency and standards

Users should not have to wonder whether different words, situations, or actions mean the same thing. Follow platform conventions.

If anything, as website use has exploded since this rule was written, the list of shortcuts and visual cues available to users has hugely expanded to include icons and formats as well as language. The magnifying glass icon is a recognisable visual cue for site search. “Add to cart” and “add to basket” are uniformly understood on eCommerce websites. There is a convention that logos should be clickable to the return the visitor to the site homepage. Breaking these mental models- or applying conventions to new outcomes- should be avoided. So, #4 is still valid.


  • Look at your calls to action- are they clear? Using buttons provides a focus for clicks or taps.
  • Do you vary the colour, language and form you use for similar interactions throughout your site? Using a consistent format that flows from page to page helps communicate meaning to your users.
  • Do you use checkboxes for one form of selection and dropdown menus for another? Try not to layer up cognitive load for users- duplicate the formatting of repetitive actions.


#5: Error prevention

Even better than good error messages is a careful design which prevents a problem from occurring in the first place. Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action.

Remember that strictly speaking it’s not a user’s fault if they’ve moved into an error state, it’s just that a designer has failed to anticipate an outcome. Don Norman (the other partner in Nielsen Norman Group) states that here are two main types of error state, slips and mistakes.  A slip made when the user is on autopilot e.g. a misspell. A mistake is made when the wrong inference is taken from the design, e.g. completing a form will generate a call back.

In the example above, B&Q anticipates that spelling mistakes are common by providing autosuggest of popular searches as the user types in the search box. This minimises mistakes and slips as users can review the options provided before fulfilling their search. In summary, Nielsen #5 still holds up.


  • Do you accommodate common errors such as misspells?
  • Do you use tooltips to clarify the meaning of more complex interfaces, or how to guides to show users how to interact?
  • Do your forms ignore conditional formatting, such as users adding brackets or addition signs to phone number fields?

Next time, we’ll look at Nielsen 6 to 10, and also show you our own quick visual heuristic framework. In the meantime, as you start your own heuristic journeys: happy hunting.

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