As science teachers, our most important goal should be to guide students in developing their ability to apply fundamental scientific principles and logical reasoning to formulate and test scientific hypotheses, as well as the analytical and critical reasoning skills to interpret the results. Unfortunately, the pressures of large class sizes and doing more with less frequently induces instructors to employ multiple-choice tests as their primary, and sometimes exclusive, format for assessing student progress. (Titled "Distracters or Detractors? What’s the Catch?" in print version.)
Synthesizing versus Selecting
Perhaps the most important transition that any student of science must make is the leap from consumer to producer. Most students majoring in science, technology, engineering and math areas have the capacity to become quite adept at absorbing and utilizing existing information and methodologies. Although such technical knowledge and proficiency generally is sufficient to obtain a degree and become gainfully employed as a member of the supporting cast, becoming an originator of new facts, new concepts and new technologies requires the capacity to engage in creative and analytical thought on a routine basis.
"If Charles Darwin had been trained in a system overly reliant on multiple-choice testing, would he ever have conceived of natural selection?"
I generally like to initiate a discussion on the nature of science by asking, “How can a scientist have confidence in the answer they obtain when asking a question that never has been raised before?” Because students are all about getting the “correct” answer, this question places the issue in a very practical and familiar context. How do you prepare for an exam or complete a homework assignment in a course for which no assigned text or answer key exists, and no authority figure is available to confirm or deny the validity of your answer?
As science teachers, our most important goal should be to guide students in developing their ability to apply fundamental scientific principles and logical reasoning to formulate and test scientific hypotheses, as well as the analytical and critical reasoning skills to interpret the results. It therefore would appear reasonable to expect STEM curricula to be replete with exercises and questions that challenge students to draw upon these skills to synthesize an original response. Unfortunately, the pressures of large class sizes and doing more with less frequently induce instructors to employ multiple-choice tests as their primary, and sometimes exclusive, format for assessing student progress.
I Thought You Were Trying to Trick Me
Unfortunately, picking from a list of prepared responses falls well short of providing students with a chance to exercise their abilities to draw upon their knowledge and reasoning skills to generate an answer whose origins are indigenous to their own intellect. Moreover, in attempting to increase the sophistication of the thought processes required to select the correct answers on a multiple-choice test, instructors often exacerbate the situation by choosing inappropriate “distracters” (the alternative answers from which the student must select).
One form of distracter that can do more harm than good is to append some mysterious condition such as, “Choose the most correct answer from the choices given below.” What is the definition of “most correct”? Doesn’t the perception of which of the correct answers is the “most” correct depend upon (frequently unmentioned) circumstances? Another common distracter is the “parade of permutations”: a), b), c); both a) and b); b) and c) but not a); none of the above or all of the above. Both of these rubrics share the property of transforming normally correct answers into incorrect ones. In the first case, one can select a perfectly correct answer and receive no credit because it was not the “most” correct. Similarly, if both a) and b) are correct, a student who recognizes that a) is correct or b) is correct, but not that both are, receives the same zero score as a person who marked c) or “none of the above” even though the former responses betray greater insight into the correct answer.