The document provides examples of three types of recommendation letters - mediocre, good, and outstanding - for a hypothetical student named Mr. Smith. The mediocre letter briefly states that Mr. Smith worked in the author's lab for one summer and completed assigned tasks. The good letter describes Mr. Smith's work ethic and interpersonal skills in more detail. The outstanding letter provides specific examples and anecdotes that demonstrate Mr. Smith's hard work, creativity, problem-solving abilities, and excellent interpersonal skills. The author expresses their strongest possible recommendation for Mr. Smith and hopes to write a similarly outstanding letter for the reader.