Proofreader applicants are tested primarily on their spelling, speed, and skill in finding errors in the sample text. Toward that end, they may be given a list of ten or twenty classically difficult words and a proofreading test, both tightly timed. The proofreading test will often have a maximum number of errors per quantity of text and a minimum amount of time to find them. The goal of this approach is to identify those with the best skill set.