Three basic schemes under which knowledge may be organized: (1) Declarative knowledge is about how and why the things work the way the do, and their names and locations. It may also include information about concepts and elements (and relationships between them) relating to particular subjects. (2) Procedural knowledge details steps or activities required to perform a task or job. This type of knowledge transforms into automatic (habitual) processes with repetition, allowing a task to be performed without conscious action. (3) Structural knowledge is basic to problem solving. It is required in creation of plans and strategies, setting conditions for different procedures, and in determining what to do when failure occurs or when a piece of information is missing.