Understandable principle

This principle speaks to the need for web content to be clear, predictable and intuitive, while allowing for error validation, prevention and correction on interactive elements (e.g. forms). It involves:

• declaring language of the page as welll as parts of a page (as needed)
• not changing page context unless specifically initiated by the user
• ensuring components appear/operate in predictable and consistent ways
• helping users identify and correct as well as avoid input errors

3.1.1 - Language of page
3.1.2 - Language of parts
3.2.1 - On focus
3.2.2 - On input
3.2.3 - Consistent navigation
3.2.4 - Consistent identification
3.3.1 - Error identification
3.3.2 - Labels or instructions
3.3.3 - Error suggestion
3.3.4 - Error prevention (legal, financial, data)