How do I write a fair and rigorous peer review?

You can read a paper and follow it. But turning that reading into a genuine critical review, one that is both fair and rigorous, feels like a different skill entirely. It is. Reading takes in what is there; reviewing means weighing it against what should be there, and no one is born knowing how. A good review is not about finding fault or proving you are clever. It asks a few plain questions of the work. Is the claim clear? Does the evidence actually support it? What are the weaknesses, and do they sink it or just limit it? Rigor is thoroughness in asking these; fairness is judging the work for what it tried to do, not what you wish it had done. Start with a simple structure: summarize the paper's main claim in your own words, list what it does well, then list your specific concerns with reasons. Point to the exact place each concern lives. That framework turns a vague sense of the paper into a fair, useful review. The skill grows with each one; you learn reviewing by reviewing.