In Architecture, a particular model of "learning buildings" was proposed that comprises six constructional layers that change at different rates. The more these layers can evolve without requiring changes to other layers, the more adaptable the building is. By analogy, organising the constructional components in an information system into layers that share similar likelihood of change may lead to systems that are easier to adapt in the face of change. If this view is accepted, then the act of analysing and designing information systems should have as a central aim the identification of layers or categories of domain elements that have similar rates of change within any one layer.