Q: In a research study what will help you to identify the potential weakness of the study
Firstly, we have edited your question slightly for enhanced clarity. Also, your question is quite broad-based. That is, the answer to it could actually be any aspect of the study – any flaw (or flaws, as a study may have multiple) may have several sources. It could be due to the methodology, to biases that you may not be guarding against, or the problem statement itself. At times, it may also depend on the researcher’s experience/expertise (or the lack of it). While experience/expertise comes from conducting actual studies, it may also be gained from regularly going through other papers or even taking up courses that help build your research acumen.
Coming to your actual question, based on your field or area of study, you may consider a pretest, computational modelling, or a dipstick (if your work is closer to social sciences or business/economics). The best method though (in case you aren’t entirely sure or wish to get a second opinion) is to have someone else review your study – a senior, a supervisor, or even a peer (if they have greater knowledge of some aspect of research that you don’t). Additionally, you may also consider using an experimental design service or a statistical review service (depending on the aspect of your study you wish to improve) to review and suggest improvements.
Overall, you have a valid concern. You wish to be as sure as possible of your design and study before embarking on it, to save (or at least, to best utilize) precious time, money, and effort. It’s always better to identify and rectify potential flaws before the study than to write the limitations of the study after it is over. However, the latter is useful in its own way, as that can lead to a follow-up study, where you can fix the issues of the previous study. In any case, most research is progressive and incremental. :-)
Hope that helps. All the best for your study!