<Google translation from Danish>
9 overall principles of usability can help ensure that users can complete their errands on websites in an effortless and satisfactory manner. The 9 principles are:
- Usage signaling
As simple as possible. Not overwhelming. No superfluous action steps.
Only what is needed
Redundant elements make a user interface unnecessarily cumbersome to overlook and increase the risk of errors. Items that do not support a mission or purpose should therefore be eliminated (not just hidden).
Limited number of options
Many choices mean that it takes longer to choose between them ( Hick’s law ), and sometimes it completely prevents users from making a choice ( Paradox of choice ).
Interaction with unnecessary action steps increases time consumption and the risk of errors.
Good default settings ( defaults ) simplify interaction.
Uniform and recognizable presentation and interaction. Corresponds to users’ expectations.
The user interface and system responses must be consistent with users’ expectations. Users have a mental model of how a website works, even before they get into it. Mental models are shaped i.a. of users’ experiences with other websites.
Uniform elements and features should be presented and work in a consistent manner on the same website.
The user interface should be designed in accordance with conventions. It makes it easier to learn how to use a website for new users.
Consistency over time
Drastic redesign makes use difficult for returning users, while ongoing minor changes better ensure consistency over time.
Visible elements, not hidden. Designed and positioned so that they are easy to spot.
Graphical user interfaces ( GUI ) are based on visibility. If items are hidden, users should either look for them or remember their location. It is easier to recognize elements than to remember them.
The location of items can make them difficult to spot. This may be because an element is located on the periphery of users ‘field of view – or another element that acts as an equally good bid attracts users’ attention. Although items are not hidden, they can be difficult to detect.
Size, clarity and highlighting affect whether users notice an item.
Large images, boxes, horizontal lines and white air can give users an experience of having reached the bottom of a web page ( illusion of completeness ) and thus stop them from scrolling on to elements further down the page.
Division, categorization and grouping according to users’ needs and logic. Natural order.
The feeling of overwhelm can be minimized by splitting when simplicity cannot be achieved by removing elements.
Lack of categorization, as well as a categorization that seems illogical, complicates navigation.
Items that belong together should be grouped.
Logical ordering of items in an overview makes it faster for users to find what they are looking for.
Taxonomies, keywords, and other forms of meta-data can help users locate large amounts of information when searching.
Understandable, accurate and unambiguous communication. Clearly several elements. Clear context.
Text, links, labels and menu items create confusion if they are incomprehensible, inaccurate, ambiguous or too general.
The difference between several similar elements can be difficult for users to understand, even if words and descriptions in isolation are clear. Comparison and selection presuppose that the difference in elements is clearly described.
Incomplete or missing information – including missing help texts and missing feedback – gives ambiguity.
Context can affect understanding and clarity. The combination of texts, images, menu items, etc. may result in a different decoding than if the elements were presented individually. The same concept can have different meanings for different user groups.
Website navigation, texts, images, etc. must together make it clear what a website or a web page is about.
Visual language can also be clear or obscure. Icons, images and highlights can be more or less self-explanatory. (Clarity can also relate to other senses).
The user and not the system controls. Appropriate pace. Actions can be undone.
The experience of having control is the prerequisite for users to feel that it is nice to use a system. Automatically changing elements can be distracting.
The pace of interaction must be controllable by users. There is not one pace that suits all users.
Undo options should be available when users make mistakes or change their minds.
Signal for usage signal
Instructions for use. Interactive elements signal how to use them.
Interactive elements should be as self-explanatory and intuitive to use as possible. It should not be necessary to read instructions to see how basic functions are used.
Signaling of interactivity
Interactive elements should be designed so that they clearly signal how they are used. Are they clickable, can they slide , can you enter anything?
No misleading signaling of interactivity
Elements that are not interactive should not signal that they are. Users must be able to clearly distinguish interactive elements from non-interactive ones.
Sensible interpretation of users’ entries, clicks and presses. Small mistakes are ignored.
The system allows variations in user input and interprets what users are trying to achieve in a sensible way.
Insignificant errors by users are ignored by the system.
Extended clickable areas
Click and click tolerance can be achieved by extending the clickable area of an element.
Physically easy to use. Challenges and does not exceed motor and sensory abilities.
Interaction should be adapted to human physics. A user interface that forces users to physically awkward and cumbersome actions increases the risk of errors and negatively affects users’ pace and satisfaction.
Items should be large enough to be easy to hit.
Elements to be used in extension of each other should stand close to each other so that users do not have to make unnecessarily large movements.
Ergonomics can also be about visual conditions: good contrasts and sufficiently large size of text and other elements.
The 9 principles for webusability have been identified by analyzing 299 usability problems on Danish websites. The usability tests include websites from both the public and private sectors, intranets, mobile websites and prototypes and were conducted between 2012 and 2015.
Heuristics have been used in the design of user interfaces since the 1990s. Older heuristics sets are still inspiring to read, but they are designed based on usability issues in software. Phenomena such as feedback and error handling therefore take up a lot of space.
On websites, navigation, content and visual design play a bigger role than in software. The 9 principles of webusability make it easier to categorize issues related to these matters.
Feedback, error messages and help texts are described in many heuristic sets with independent principles. In our system, these components are just objects for evaluation just like a website’s navigation, content and functions. An error message can, for example, be visible, clear, simple, etcusa