Subordination in outlines shows the relationships between a writer's various ideas. A well-considered outline uses indentation and a system of numbers and letters to show that some ideas are more important than others. Outlines also show how a writer's ideas and arguments fit together coherently. A properly subordinated essay lays out the structure of an essay or other paper in useful levels of detail.
Outlines can be subordinated down to the sentence level, but need not be. They should never be taken farther, to the point where they become more intricate than the essay they support.
Each level of an outline should have at least two items. If one level does not, the outline should be restructured. An outline shows how the topics in a piece are divided up. If there is no division at a certain level, that level has no reason to exist. Proper division will maintain a balance between the sections of a piece.
To properly illustrate structure, an outline uses capital and lower case letters, as well as Roman and Arabic numerals. Each new level of detail, as the outline proceeds from major points to minor supporting details, is indented farther. Usually, indentations are one tab stop each, about one half inch. Word processing programs can do most of the work of indenting outlines.
Outlines proceed from Roman numerals to capital letters, and then to Arabic numerals. For still greater detail, use lower case letters followed by a single right parenthesis, then Arabic numerals enclosed in parentheses, then lower case Roman numerals followed by a parenthesis.
Types of outlines
Outlines may use phrases or sentences. A sentence outline uses a complete sentence for each idea. This kind of outline describes each idea fully, but takes more time to create.
A topic outline uses a phrase at each level, meaning that writers have to rely on their memories to supply the full import of a phrase they scratched down. This is faster to produce, but it may need more work later to flesh out its ideas.
In a topic outline, phrases begin with a capital letter, but have no end punctuation. Only a sentence outline uses a period at the end of each item.
An outline helps a writer create a logical argument or a coherent story. The discipline of placing each supporting point beneath its proper heading or each consequence after its cause is what makes an outline an effective way to plan almost any kind of writing.
Once a properly subordinated outline is complete, the structure of an essay is clear. The main points of the argument are farthest to the left. They are supported by an array of facts and arguments at the next level to the right, and of the next level of importance. Those arguments in turn are bolstered by more detail, so that the whole produces a cogent, unified article or essay in which each sentence knows its place and fulfills its role.