The function of the abstract of a scientific research paper is to provide an overview of the paper. The overview should present the main story and a few essential details of the paper for readers who read only the abstract and should serve as a clear preview of the main story for readers who read the paper. Thus, the abstract should make sense both when read alone and when read with the paper.
The abstract should be neither vague and general on the one hand nor fussily detailed on the other. Rather, it should be specific and selective. As its name suggests, an abstract (ab, out + trahere, to pull) should select (pull out) the highlights from each section of the paper.
Sometimes the overview in the abstract is clearer than the overview in the text. The reason is usually either that part of the overview is omitted in the text or that the details in the text obscure the overview. Although the author should make every effort to weave a clear overview into the text so that the text does not become all trees and no forest, an advantage of having a clear, concise overview in the abstract is that it can compensate for some lapses in the overview in the text.
ABSTRACTS OF HYPOTHESIS–TESTING PAPERS
The abstract of a hypothesis-testing paper should state concisely the question that was asked, the experiments that were done to answer the question, the results that were found that answer the question, and the answer to the question. In addition to these four basic parts, the abstract may begin with a sentence or two of background information to help the reader understand the question and may end with a sentence stating an implication of the answer or a speculation or recommendation based on the answer. Because the abstract must make sense when read alone, as well as when read in conjunction with the paper, the abstract should not include citations of the scientific literature or citations of figures or tables.
State the question you asked either as a question or as a hypothesis.
The Experiments That Were Done
Name the material studied (molecule, cell line, tissue, organ) and the organism from which it came, or name the animal or human population studied. If necessary, include the condition of the animals or subjects, such as anesthetized.
State the experimental approach or the study design, including both the independent and the dependent variables. Mention only important details of materials and methods.
The Results That Were Found
Include only results that answer the question. Give data, if at all, only for the most important results. Give percent change rather than exact data when possible. ...