IMRAD Format:
A standard format has evolved for presenting the results of scientific research. It is commonly called IMRAD, an acronym for the main sections into which it divides a paper — introduction, materials and methods, results, and discussion. The Introduction explains what research was carried out and why. This page also links to notes on library research. The Materials and Methods details how the study was performed. Results presents a summary of the data collected, and Discussion interprets the results, and puts them in context with previous research. Although variations exist depending on the type of study and the scientific discipline, this format is commonly used throughout the physical sciences.
The methods and results sections actually describe the experiment, and so are normally written in past tense. (This is what we did and what we found.) The introduction and discussion sections “frame” the experiment and put it in context. The introduction describes the state of our knowledge before the current experiment was performed, while the discussion reflects on how our understanding of the field has been changed by the new experiment’s results (Penrose and Katz 1998). Introduction and discussion are normally written in present tense. (This is what we know.)
Historically, most scientific papers were written in passive voice (It was discovered that…) rather than active voice (We discovered that….). Today many journals prefer active voice as a shorter and clearer way to structure sentences in most instances . However some journals (and some scientists) still prefer passive voice, and there are circumstances in which passive voice can be clearer, by giving greater emphasis to the object being manipulated (Fertilizer was added to each plant….) rather than the person doing the manipulation (I added fertilizer to each plant…)(Penrose and Katz 1998). Choose the voice which is appropiate to your topic, and preferred by the journal or instructor to whom you will submit your paper.
Subheadings within a section are generally acceptable, and are useful when more than one experiment is being described.
General Layout:
Information in papers can be presented in one of three forms:
Text: Presented in paragraph form. Bulleted or numbered lists are not generally appropriate.
Tables: Information, usually data, organized in rows and column, with an explanatory title at the top. All tables should be referenced at the appropriate place in the text, and should be numbered in order that they are referenced. Tables are either inserted in the text close after the point at which they are referenced, or collected at the end of the paper. See Results for more details.
Figures: Information presented visually, such as drawings, maps or graphs, with an explanatory caption at the bottom. All figures should be referenced at the appropriate place in the text, and should be numbered in order that they are referenced. figures are either inserted in the text close after the point at which they are referenced, or collected at the end of the paper. See Results for more details.
Resources:
Science Toolkit resources on the research paper look at each of the IMRAD sections in turn, but also include several additional pages. The first considers how and why to prepare an Outline. A few brief notes are included on choosing a Title, and another short page examines how to write an Abstract. More detailed notes are provided on the “meaty” sections — Introduction, Methods, Results and Discussion. Citing references is described in the Literature Cited section, and a final resource looks at some Common Problems in student papers.
Keep in mind that in the end, the best way to learn how to write research papers, is to read research papers from the primary literature. Only after reading a wide selection of papers from various disciplines will you begin to get a “feel” for the style used in reporting scientific research.