To be effective, scientific and technical documents have to limittheir scope, the depth and breadth of theirinvestigations. A scientific or technical report limits thescope of its discussions in response both to the boundaries ofthe inquiry itself and to the purpose and expertise of itsaudience. See Document Density.
A short statement of the scope of a document, describing whatwill be discussed, and what will not be discussed is oftenincluded as part of the introduction. In thefollowing example, the author narrows the scope of the discussionof neural systems that control locomotion from humans or animalsin general to one specific vertebrate, the lamprey.
Since the late 1960s, my colleagues and I have beenattempting to unravel the design of the neural systems thatcoordinate locomotion in various experimental animals in hopesthat this research will help scientists understand some of theintricacies of the human nervous system. Much is yet to belearned, but we have finally produced a blueprint for the neuralnetworks responsible for movement in a simple vertebrate, a typeof jawless fish known as a lamprey.
--Sten Grillner, "Neural Networks for VertebrateLocomotion," Scientific American
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