Passage Summary: A university shouldn't have classes that are too big or too small, and professors shouldn't have too much or too little work, because the extremes make it hard to keep the school running well.

Conclusion: Universities should avoid the extremes of very large or very small class sizes and very light or very heavy teaching loads.

Reasoning: Large classes and heavy teaching loads undermine a university's ability to attract and retain quality students and faculty.

Analysis: Notice the 'missing pieces' in the evidence provided. While the author explains why large classes and heavy loads are bad, they completely ignore why small classes or light loads are problematic. To guarantee the conclusion is true, we need a premise that explains why those other extremes are also harmful to the university. Look for an answer that provides a reason to avoid the 'small' and 'light' ends of the spectrum.