Ambiguity
What does the grade really mean?
Make it harder
True/false tests are used to measure a student’s ability to recognize facts, cause and effect relationships, principles and so on. As with the short answer types, they may be given orally. However, while it seems a simple way to make a test covering a great may facts, there are two serious flaws. First, the statements must be absolutely unambiguous. This is very hard to accomplish, since even your best students will be reading the questions from a somewhat different frame of reference. Secondly, a student could presumably get 50 percent right by sheer guessing alone. Or, putting it another way, imagine a true/false test with 100 questions. Let’s say the student knows the answers to 40 questions. He then correctly guesses half the remaining 60 questions. The original 40 plus the correctly guessed 30 would give him a score of 70%. The grade, 70%, would seem to imply he knew that fraction of the material when, in fact, he only knew 40%.
You can diminish the effectiveness of guessing on true/false tests by providing for a third choice such as “Sometimes True”. However, if you do this, be certain that this answer is correct some of the time; otherwise the kids will quickly learn it’s only a distraction. Avoid using direct copies of sentences in the textbook. Otherwise, you’ll only be testing recognition as opposed to understanding. Finally, if you use words such as “never”, “no”, or “always”, be sure to include them in correct as well as in incorrect statements.