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An abstract is a brief summary of a research article, thesis, review, conference proceeding or any in-depth analysis of a particular subject or discipline, and is often used to help the reader quickly ascertain the paper's purpose. When used, an abstract always appears at the beginning of a manuscript or typescript, acting as the point-of-entry for any given academic paper or patent application. Abstracting and indexing services for various academic disciplines are aimed at compiling a body of literature for that particular subject.
The terms précis or synopsis are used in some publications to refer to the same thing that other publications might call an "abstract". In management reports, an executive summary usually contains more information (and often more sensitive information) than the abstract does.
Academic literature uses the abstract to succinctly communicate complex research. An abstract may act as a stand-alone entity instead of a full paper. As such, an abstract is used by many organizations as the basis for selecting research that is proposed for presentation in the form of a poster, platform/oral presentation or workshop presentation at an academic conference. Most literature database search engines index only abstracts rather than providing the entire text of the paper. Full texts of scientific papers must often be purchased because of copyright and/or publisher fees and therefore the abstract is a significant selling point for the reprint or electronic form of the full text.
Abstracts are protected under copyright law just as any other form of written speech is protected. However, publishers of scientific articles invariably make abstracts publicly available, even when the article itself is protected by a toll barrier. For example, articles in the biomedical literature are available publicly from MEDLINE which is accessible through PubMed. It is a common misconception that the abstracts in MEDLINE provide sufficient information for medical practitioners, students, scholars and patients. The abstract can convey the main results and conclusions of a scientific article but the full text article must be consulted for details of the methodology, the full experimental results, and a critical discussion of the interpretations and conclusions. Consulting the abstract alone is inadequate for scholarship and may lead to inappropriate medical decisions.
An abstract allows one to sift through copious amounts of papers for ones in which the researcher can have more confidence that they will be relevant to his or her research. Once papers are chosen based on the abstract, they must be read carefully to be evaluated for relevance. It is commonly surmised that one must not base reference citations on the abstract alone, but the entire merits of a paper.
An academic abstract typically outlines four elements relevant to the completed work:
It may also contain brief references, although some publications' standard style omits references from the abstract, reserving them for the article body (which, by definition, treats the same topics but in more depth).
Abstract length varies by discipline and publisher requirements. Typical length ranges from 100 to 500 words, but very rarely more than a page and occasionally just a few words. An abstract may or may not have the section title of "abstract" explicitly listed as an antecedent to content. Abstracts are typically sectioned logically as an overview of what appears in the paper, with any of the following subheadings: Background, Introduction, Objectives, Methods, Results, Conclusions. Abstracts in which these subheadings are explicitly given are often called structured abstracts by publishers. In articles that follow the IMRAD pattern (especially original research, but sometimes other article types), structured abstract style is the norm. (The "A" of abstract may be added to "IMRAD" yielding "AIMRAD".) Abstracts that comprise one paragraph (no explicit subheadings) are often called unstructured abstracts by publishers. They are often appropriate for review articles that don't follow the IMRAD pattern within their bodies.
The hydrodynamics of dolphin drafting
by Daniel Weihs, Faculty of Aerospace Engineering, Technion, Israel Institute of Technology, Haifa 32000, Israel.
Background Drafting in cetaceans is defined as the transfer of forces between individuals without actual physical contact between them. This behavior has long been surmised to explain how young dolphin calves keep up with their rapidly moving mothers. It has recently been observed that a significant number of calves become permanently separated from their mothers during chases by tuna vessels. A study of the hydrodynamics of drafting, initiated inmechanisms causing the separation of mothers and calves during fishing-related activities, is reported here.
Results Quantitative results are shown for the forces and moments around a pair of unequally sized dolphin-like slender bodies. These include two major effects. First, the so-called Bernoulli suction, which stems from the fact that the local pressure drops in areas of high speed, results in an attractive force between mother and calf. Second is the displacement effect, in which the motion of the mother causes the water in front to move forwards and radially outwards, and water behind the body to move forwards to replace the animal's mass. Thus, the calf can gain a 'free ride' in the forward-moving areas. Utilizing these effects, the neonate can gain up to 90% of the thrust needed to move alongside the mother at speeds of up to 2.4 m/s. A comparison with observations of eastern spinner dolphins (Stenella longirostris) is presented, showing savings of up to 60% in the thrust that calves require if they are to keep up with their mothers.
Conclusions A theoretical analysis, backed by observations of free-swimming dolphin schools, indicates that hydrodynamic interactions with mothers play an important role in enabling dolphin calves to keep up with rapidly moving adult school members.
© 2004 Weihs; licensee BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL
The informative abstract, also known as the complete abstract, is a compendious summary of a paper's substance including its background, purpose, methodology, results, and conclusion. Usually between 100 and 200 words, the informative abstract summarizes the paper's structure, its major topics and key points. Informative abstracts may be viewed as standalone documents.
The descriptive abstract, also known as the limited abstract or the indicative abstract, provides a description of what the paper covers without delving into its substance. A descriptive abstract is akin to a table of contents in paragraph form.
During the late 2000s, due to the influence of computer storage and retrieval systems such as the Internet, some scientific publications, such as Journal of Colloid and Interface Science, started including graphical abstracts alongside the text abstracts. The graphic is intended to summarize or be an exemplar for the main thrust of the article. It is not intended to be as exhaustive a summary as the text abstract, rather it is supposed to indicate the type, scope, and technical coverage of the article at a glance.