Questions to ask when reading/reviewing a scientific paper:

1. What questions does the paper address?
2. What are the main conclusions of the paper?
3. What evidence supports those conclusions?
4. Do the data actually support the conclusions?
5. What is the quality of the evidence?
6. Why are the conclusions important?

I suggest the following subquestions:

• If the paper contains a hypothesis, is it falsifiable?
• (How) Is the work reproducible? (what would you need to reproduce it?)
• What does the paper contribute to the existing body of knowledge?
• Are the applied methods explained, valid and reliable? (e.g. statistical tests)
• Are the limitations of the work acknowledged?