These words refer to sets of ideas developed to accomplish a desired result. Plan is quite informal and the most general. It can refer at one extreme to a tentative, unverbalized cluster of notion, and, at the other, to a detailed final draft stating the precise methods by which to proceed: a vague plan to go there sometime; plans for a merger that filled two filing cabinets. Scheme is also informal, but is restricted in meaning either to a vague, unverbalized notion or to surreptitious or unsavoury ideas. Unworkability may be implied in the former case, conspiratorial plotting in the latter; coming up with scheme after scheme for getting rich quick; their carefully worked out scheme for assassinating the Prime Minister.

Design and blueprint both relate to that side of plan that suggests a detailed final draft. Design can suggest harmony and order as the salient feature of the plan ; it can also suggest a symbolic rather than literal rendering of the work to be don: a building noteworthy for its simplicity of design ; a master who made the grand design but left his apprentice to fill in the details. Blueprint , by contrast, suggests minute attention to every last detail: a complete blueprint for enforcing the new security regulations.

Proposal can suggest tentativeness, like plan , but it strongly implies a context of collaboration through discussion, or a hierarchic situation in which approval of a plan must first be obtained: a proposal for spending the afternoon in the park; a proposal approved by the committee but defeated at the general meeting. Programme may suggest a detailed set of proposals , but, alone of all these words, it most specifically suggests a plan that is actually being carried out: the tenth anniversary of the conservation programme .