I would strongly encourage undergraduates, graduate students, and more colleagues than I can mention in this blog post to amble over and read Farrell's essay. He lives up to his own principles by having a clear and concise opening:
Leo Tolstoy famously observed that “happy families are all alike; every unhappy family is unhappy in its own way.” Tolstoy, happily for all of us, was not a teaching political scientist. Had he been, he might have observed that undergraduate political science papers are subject to a different logic. Really good papers are unique - each has its own particular thesis, style of argumentation, body of empirical evidence and set of conclusions. Really bad papers, in contrast, tend toward a dismal uniformity. They draw on the same evidence and arguments (garbled versions of what the professor has presented in class), are organized according to similar principles of incoherence, and all wend their eventual ways towards banal conclusions that strenuously avoid making any claims or positive arguments whatsoever.