These words refer to pieces of non-fiction writing. Composition indicates a formal work that is planned in advance rather than improvisatory in character. It is used to refer any sort of writing assignment in school, often on a set subject, with an emphasis on grammar and style rather than on research or factual presentation: The teacher asked them to describe their summer holidays in the class composition . Exercise is a less formal word and is restricted in reference to such an assigned piece of writing in school. The word emphasizes organization round a single topic, may suggest briefer treatment, and is even less likely than composition to require factual research: a class exercise of three hundred words. Theme is sometimes used in a similar sense, but this word’s main function is to refer to the dominant idea of any piece of writing: the theme of alienation in his study of middle-class culture.

Essay is a much more general word than those above. While it may be used in place of any of them to refer to a writing assignment in school, the word more widely indicates any sort of non-fiction writing shorter than book-length, whether scholarly, humorous, propagandist or reflective. The word, moreover, may suggest any approach from the extremely informal and personal to the solemn, stately or stylized: the refreshing irreverence of Addis’s chatty essays ; the Ciceronian elegance that Carlyle attempted in his early essays ; howlingly funny about the perils of suburban living. Article is restricted to any piece of non-fiction that has appeared in a newspaper, magazine or journal; it ranges in reference from the briefest and most utilitarian news release through all the possibilities inherent in essay , including the more abstruse scholarly or scientific study: an article giving up-to-the-minute election returns; an article treating the effects of radiation on arthropods.

Paper has two areas of relevance. One relates to composition or exercise in referring to a written assignment for a school class or to a tutorial exercise for a university group.

• His paper was well received by the class.

In this use, the word may suggest any sort of approach, from a demonstration of writing ability to the presentation of factual research. The word’s other use refers to a scholarly essay read to one’s colleagues or to a scholarly article published in a learned journal: a paper on disturbances in the earth’s magnetic field. Treatise indicates an exclusively scholarly context, referring to any presentation from essay - to book-length in which conclusions are drawn from a body of data in a formal and systematic way: a treatise on the development of the Gregorian chant.

The remaining pair of words also is restricted to a scholarly or academic context. Thesis may suggest briefer or less exhaustive treatment that treatise , pointing to the establishing and defending of a principle: a thesis in which he corroborates Keynes’s theory of deficit spending. Like theme , thesis may also refer to the dominant idea of contention of a piece of writing, although it pertains mainly to argumentative non-fiction: a collection of essays each of which illustrates his thesis that modern novelists are unable to create memorable women characters. Most concretely, thesis refers to the extended paper, possibly of book-length, that is sometimes required of candidates for a Master’s degree and always for a Ph.D. degree. Dissertation is the most formal of these words and, when used instead of thesis, suggests the most formal sort of writing as well. It may refer to any reasoned treatment, like treatise , but most concretely it indicates such a work, usually of book-length, when it is a requirement for a Ph.D. or other doctoral degree: a dissertation analyzing cold-war strategies. The word may sometimes be used pejoratively for any long-winded and pompous piece of exposition; giving us another dreary dissertation on the evils of imperialism.