In their book, Writing scientific research articles: strategies and steps, Margaret Cargill and Patrick O’Connor highlight that research papers in many fields often use one of the following structures.
Margaret Cargill and Patrick O’Connor draw these structures as shown in the following link (see the four figures on Pages 12, 13, 14 and 15).
The shape of these paper structures is reminiscent of an hourglass timer. The width of these paper structures represents the broadness of the viewpoint.
In all cases, the narrowest parts of the paper structure are the Results and Materials / Methods sections. That’s because the viewpoints in these sections are specific: they only cover the results in the current paper, and they only cover the materials or methods relevant to collecting and analyzing the results in the current paper.
In all paper structures, the width of the Introduction section of the paper ends at exactly the same width as the Results section. This means that whatever broader viewpoint is taken in the beginning parts of the Introduction section, by the end of the Introduction section, that viewpoint has narrowed to focus specifically on whatever results will be presented in the paper (the structure of Introduction sections will be covered in depth in Sub-step 7.2).
On the flip side, the width of the Discussion section of all paper structures commences at exactly the same width as the Results section. This means that the Discussion section commences with a specific focus on the Results of the paper (often with a statement of the main results), and then takes a progressively broader viewpoint towards the end of the Discussion section, with generalizations from the results and what they mean in the context of the broader field (the structure of Discussion sections will be covered in detail in Sub-step 8.1).
These IMRaD (AIMRaD) / AIRDaM / AIM(RaD)C / AIBC paper structures encourage authors to write papers as if the results they observed are exactly the results they were looking for in the first place. While this may seem like ‘cheating’ (researchers know that research rarely goes in such a predictable way, hence the development of things like clinical trial registries), this convention on paper structure makes it easier for readers to quickly understand the research.
If you picture this IMRaD (AIMRaD) / AIRDaM / AIM(RaD)C / AIBC paper structure while you’re writing your paper, you’ll save a lot of time.