An effective thesis is arguable—a generalization; it is not a fact.

A thesis must prepare readers for facts and details, and it cannot itself be a fact. A thesis must always be a generalization for which a reasonable person would expect support or further development.

Too Factual: “Today’s professional athletes have set new records.”

Revised: “To understand why the peak performances of today’s athletes are so superior to those of athletes of fifty years ago, one has to consider multiple factors: training, nutrition, coaching, and the huge salaries earned by today’s stars.”

Hairston, Maxine, and John J. Ruszkiewicz. The Scott, Foresman Handbook for Writers. New York: Harper Collins, 1996. 32.