Research on the effects of questioning in the classroom has explored the placement, timing, type, and social impact of questions. Principles of good questioning include the following: (1) well-stated questions should be concise, clear, and complete; (2) questions should be topical in nature, requiring a complex answer; (3) yes or no questions should be avoided; (4) leading questions should be used sparingly; and (5) elliptical or "fill in the blank" questions should be avoided. Several studies indicate that while some questions before reading are appropriate and desirable, questioning before reading can limit what the less able reader comprehends, although the opposite seems to be the case with good and more mature readers. The time and manner in which questions are asked may be the determining factor in a successful or unsuccessful discussion session. Generally, questions that can be answered in a variety of ways seem less threatening to students than do those with only one right answer. One study indicates that teachers use fact questions more often than any other kind. Other studies make the observation that questions may both lead a reader to better learning and understanding and lead them astray. Questions can be used in various ways and can have positive or negative effects depending upon the teacher and what the teacher is attempting to accomplish rather than upon the technique used. A differentiation must be made between the use of questions for assessment and for fomenting discussion. (HTH)