Take in mind general web standards and respect platform specifics of operation systems.
When defining the user interface, it is important to not re-invent user interface elements. Try to focus on existing web and mobile standards, or the native platform standards (iOS, Android, Windows).
When users recognize user interface elements (links, buttons, icons, access to menu, etc.) or flows (add, delete, save, open, etc.), they will easier adapt to the user interface. The same remark is valid for the placement of user interface elements. There are standard places for contact information, language choice, help, contact, etc.
By following these general conventions, the user interface will feel more intuitive, which will result in a smaller learning curve to get to know the application and the user interface will be easier to use.
Keep different screen sizes in mind.
When designing and developing a user interface, it should be consultable on all kind of devices and on all screen sizes. Make sure that the mobile design is kept in mind from the beginning of the product development lifecycle.
Emphasize where the user is located in the user interface.
When navigating through the user interface, it is important that the user knows at any time where he/she is located in the user interface. In this way, it is easier for the user to orientate and to initiate new actions. This can be done by highlighting the active category of the main navigation, repeating the active category as page title, providing a breadcrumb or highlighting the related element in the action bar of the app.
Other important guidelines to improve the ease of use of your application.
- Make sure that all user interface elements (labels/terminology/buttons/etc.) are used in a consistent way throughout the application. By improving the consistency of the user interface, your product will be considered as more user-friendly.
- Be careful when using icons as stand-alone action button or meaningful user interface element. Only icons like save, add, delete, close, search and email can be used as stand-alone icon since they are well-known and users can interpret them without accompanying textual label. For less known icons, provide always the textual label next to the icon. When in doubt, use always the textual label together with the icon.
- Don’t use colour as the only indication to express a meaning of an interface element. Colour can’t always be interpreted in an unambiguous way. Provide always an accompanying textual label when colour is used.
- Terminology and vocabulary in your application should be defined from the user point-of-view, and not company-or product point-of-view. Use a comprehensive and easy language style; using short and clear messages adapted to your uses.
- Check recommendations on wablieft.be concerning plain, understandable language.
- Any clinical or technical terms that are being used in the application should be explained clearly to the user, either within the content of the application or via a glossary. Labels in navigation or on buttons (call to actions) should express clearly what the user could expect or will do.
- Check in your application if the clickable or touchable controls (e.g. action buttons, menu, etc.) are big enough to access with ease. Change screen size to website/ tablet/ mobile and re-test to make sure they stay accessible at any time. Keep in mind specific conditions of your target users (older users have thicker fingers, trembling hand, etc.).
- Keep in mind that the size of your text in the application, on actions buttons, of items in the main and sub menu, etc. is big enough in order to facilitate the use of your application for your target audience (See more guidance in Accessibility).
- Pay enough attention to your form design. Often forms (registration form or other forms) are the last thing to design, which means that they aren’t well considered. However, those forms are often a moment of truth within the application: drop out or continue/ stay in the application. Make sure that it is indicated well which input fields are required to fill in vs. optional, don’t ask for too much information (profiles can be completed later, after the registration, when the user is more engaged to use the application), provide clear labels to all fields and don’t display the labels in the input fields.
- When designing your user interface, check the existing ISO standards, AFNOR standards, and other free accessible guidelines (cfr. links at the end of this section).
- Make sure that the user can access the application within his / her own language.
The guidelines listed in this section are important elements to observe and evaluate during (iterative) user testing sessions.