Probabilities are nothing but common sense reduced to calculation - Pierre-Simon LaPlace
We should be cautious about calculating without thinking. Calculations are the easy part. The thinking is the hard part. The important question is whether the calculations make sense. The result many times is common nonsense. Don't just do the calculations. Use common sense to see whether you are answering the correct question, the assumptions are reasonable, and the results are plausible. If a statistical argument doesn't make sense, think about it carefully - you may discover that the argument is nonsense.
