Glossary » consistency

consistency

the principle that things that are related should be presented in a similar way and things that are not related should be made distinctive. Consistency applies across quite varied contexts:

• information should be presented in a consistent way: if bold is used to provide emphasis in one part of a document, italics shouldn’t be used in another part
• input and output should be consistent (stimulus-response compatibility): pressing an up button should go up, not down
• an application should behave consistently in any context and on any platform (cross-platform compatibility)
• what one person sees should be consistent with what another person sees, so that they can effectively communicate about it (the WYSIWIS principle)
• an application should behave consistently with the metaphor that it presents: folders on a desktop may contain files, but files may NEVER contain folders