Most scientists readily admit that after reading the abstract, they skip forward to the Methods and Results sections. They want the data and how it was attained. While the Introduction and Discussion sections are the most readable parts of the paper, the Methods and Results are "science" itself. Writing needs to be accurate, sufficient, and largely free of interpretation.
Method sections vary quite a bit between disciplines, and even between sub-disciplines in the same field. Still, there are three types of information conveyed.
1. Participants/Subjects/Sample -- who participated or what material was participated upon; in current parlance, humans beings are called "participants" and animals are "subjects", though the more general "sample" can be used for both. (Other biological or non-biological components may be called "materials" or simply listed by their names, e.g. "serotonin compound, PAT", and not occur in a separate section).
NOTE: In the social and behavioral sciences, the final experimental population descriptors are listed in the Methods section. In the medical sciences, the general target population in terms of eligibility criteria and exclusion criteria is described in the Methods section -- the actual, final population who took part in the study is described in the Results section.
2. Materials and Instruments -- the instruments, machines, or materials used to complete the research -- be as specific possible. If new materials were developed, include thorough description and add an appendix with instrument, if possible (ex: surveys, stimuli).When possible, provides names and numbers of all equipment, software, etc used.
3. Procedure -- explains how data was collected and how it was analyzed, including specific names of tests, procedures, and statistical tests.
Multiple Groups -- same organization as basic, but also includes study flow chart
Randomized clinical trial examining the effect of music therapy in stress response to day surgery. Leardi, S., Pietroletti, R., Angeloni, G., Necozione, S., Ranalletta, G. and Del Gusto, B. (2007) Br J Surg, 94: 943–947. doi: 10.1002/bjs.5914