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Volume 1 |
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A Reconnaissance |
With the pressure to teach authentic science instead of ideal science, what can a science teacher do? Investigations of students' views on the scientific enterprise have explored the following questions:
(1) What conditions are necessary for successful learning?
(2) How can a teacher evaluate student views?
It is extremely important for a teacher to acquire reliable feedback about his or her own teaching.
Seldom do students pick up authentic images about science from the subtle comments or elements within a science course. Rather, the ideas about the scientific enterprise (its characteristics) and limitations must be the center of attention. Two examples will illustrate this point.
(1) If a particular lab is intended to convey that human imagination is involved in scientific model building (e.g. the "black box" lab---see page 439), then students must be asked in the lab to address the role of human imagination, they must discuss it, and they must find it part of their evaluation in the course.
(2) If your objective is to teach the distinction between science (the process of understanding natural phenomena) and technology (the process of designing techniques and implements to respond to human needs), then projects and problems must be presented to help students distinguish between science and technology.
Students will come to class with their naive ideas [alternative frameworks] about the scientific enterprise---often the conception of ideal science or scientism. These ideals or mythical notions must be challenged before authentic images can be learned. Simulations, projects, reading assignments, field trips, forums, debates and especially discussions are all appropriate teaching strategies to help them relearn or reformulate their views.
Most importantly, the teacher must realize that it usually takes a long time and considerable evidence for students to change their ideas about the nature of science. It may take a full year for students to realize that well-known scientific laws are not truths found in nature, but are man-made generalizations. It may take three years before your students develop an accurate view of the methods of authentic science.
On the other hand, ideas which are new or relatively unfamiliar to students are quickly learned. Ideas such as recognizing that the scientific enterprise is comprised of public AND private science, each employing its own set of values, may be easily assimilated by students. Similarly, students are generally amenable to learning about the social and political contexts of science.
Teachers find that activities which focus on the nature of the scientific enterprise should be introduced early in a course, thus allowing for reinforcement of these ideas during the whole course. Reasonable time taken for such activities does not adversely affect student achievement or traditional science content.
Objectively-scored types of questions do offer objectivity of scoring from the teacher's point of view, but the questions are woefully inadequate in assessing student beliefs. The students' interpretations, however, are clearly evident in their written responses. Student paragraphs, typically two to five sentences in length, are more clearly written when:
(1) students are presented with a situation or statement; then
(2) asked whether they agree, disagree or can't tell; and then
(3) asked to explain the reasons for their choice.
This second point is important because it requires the student to take a position from which to argue. Students will often change their initial choice as they write their explanations. Somewhat surprisingly similar paragraphs will be written for opposite initial positions.
Teachers trained in science are not comfortable or confident in grading student writing. Here are some guidelines aimed at removing this obstacle. First, familiarize yourself with a range of answers by reading a few responses anticipated to be good and poor. Assign three points to answers that deal with the topic in a sophisticated way, given the nature of the instructional activity and the maturity level of your class. Two different explanations may each receive three marks, as long as they are logically constructed. Seldom is an answer considered right or wrong; but is analyzed as a better or poorer response.
Zero points are assigned to poor or uniformed responses, while one or two points are awarded to more informed responses---those that reflect some degree of realistic understanding. Three points are awarded to answers that are clear, precise and logical. It is very helpful to compose a scoring scheme for each individual question.
Students usually need practice in writing paragraphs about the scientific enterprise. Homework and quizzes are useful places for this to begin. Students who are shy about writing need individual attention and encouragement. English and social studies colleagues may have suggestions for motivating students, as well as comments about scoring schemes and efficient use of marking time.