7. Layout : consistency

Consistency means that all parts of the interface layout take a similar approach to design. For instance

• All menu items behave in the same way
• Menus have a consistent colour scheme and look
• Menus are laid out in the same way
• Interface elements such as command buttons, inbox, radio buttons, combo boxes etc have a similar design
• Icons are styled in a similar way
• Background colour remains the same
• Fonts are consistent
• Headings and titles use the same size font and style (bold, italics etc)
• Margins and white space remain consistent

The fictitious example below shows an interface that breaks many of the suggestions above. Each page is well designed, but it should be no surprise that they are in fact different interfaces.

Consistency can be applied across of family of related products. For instance

• An Office suite (word processor, spreadsheet etc)
• Across company websites
• Company intranet
• Multimedia suites that can deal with images, graphics, video