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Chapter 16 – Principle 3: Understandable


Thanks for your interest in the Abra kick-off training about the accessibility of apps. My name is Paul van Workum and I am working in the field of app accessibility.

Principle 3: Understandable

Information and the operation of the user interface must be understandable. There are three guidelines.

Guideline 3.1: Readable

Specify the language of text. Specifying the language of the software is required. If part of a text is in a different language, you can also mark this. The screen reader then reads out the text in the correct language. Marking parts of text is not a legal requirement, but advisable.

Guideline 3.2: Predictable

Don’t just let the element focus change. For example, when finishing the last letter of the pincode field you automatically go to the next screen. This can be confusing and increases the risk of input errors.

Guideline 3.3: Input Assistance

Provide clear instructions and error messages. If some fields are required, mark them as required.

If an error occurs, communicate this with the user and help the user finding a solution. For example: ‘There is no network connection, please connect to the internet.’ Provide the error and also give the solution to the user.