||Within Human-Computer Interaction, it has long been speculated that inconsistent design impedes the user experience. However, defining and categorising consistency has been shown to be a challenging task. Several studies on the subject have used categorisations of consistency with mixed perspectives of the system, its developer, and its user. Consistency, however, is highly subjective. In this talk, it is therefore suggested we take a user centred approach when defining the term "consistency" and thus categorise consistency solely through the user's perspective using a simplified cognitive system approach. This then leaves us with Perceptual, Semantic, and Procedural (in)consistencies to consider when designing for interactions.