There are 6 scientific principles that are foundational in scientific thinking. Understanding what they are can help perform more focused research.
Note: While I apply these 6 principles to UX research, I believe they are applicable to many industries.
Before reaching a conclusion — before or after research — make sure that all other explanations have been considered & vetted.
In-practice: Reach out to other teams that interact with your users & research topic and understand their data and approach. Chances are there is some similarity that help focus your efforts.