One of the commonest reasons for papers to be rejected by journals is when peer reviewers consider that the method(s) could not be repeated by others.
The cornerstone of the scientific method requires that your results, to be of scientific merit, must be reproducible; and, for the results to be judged reproducible, you must provide the basis for repetition of the experiments by others. (Barbara Gastel and Robert Day)
The materials and methods section is simply a recipe. If you used a well-documented method, just cite the original author(s) and paper that described the method. If you modified or developed a new method, you should describe its validation and give a detailed description of the method – sufficient for someone else to repeat the method.
Methods should be as long and detailed as necessary, but as concise and readable as possible. The acid test of a good description is to ask a colleague if they could repeat your method after reading your description. Readers should be clear about the following:
- selection and source - materials/animals/volunteers
- study design - specifically describing temperature, time, dose, species
- outcome measures
- statistics - techniques, randomisation, power, specified p values
- ethics - approval if required (end of participant section).
Help the reader with these:
- use subheadings – often these can be similar/identical to the corresponding results
- use tables/flow charts/diagrams if needed/allowed.