David L. Haury and Peter
Rillero, 1994
Introduction
Just as an artist expands our limits of perceiving, good teachers expand our limits of knowing and understanding. Both artists and teachers inspire us to see more and wonder what other attractions might be lurking just beyond our view. Vivid images of my favorite science teacher of 20 years ago periodically refresh my remembrance of his view-extending ways.
One learning episode that often comes to mind involved a field trip to nearby mud flats along a coastal estuary. Being fond of clams, or eating clams I should say, I knew that a mud flat was not devoid of life, but it was not a place I would choose to go to "look around." What of interest, besides clams, could possibly live in such a place, and why would anyone want to deliberately investigate a place where the odors and the mud seem to have a life of their own, just waiting for unsuspecting victims?
We were studying respiration at the time and had learned several interesting laboratory techniques for determining respiration rates and estimating the volume of oxygen being respired for a given biomass. It all seemed very understandable in the controlled, aseptic conditions of the laboratory.
But as we were standing in the middle of the mud flats, the teacher asked, "How much oxygen is being respired by organisms of these mud flats?" With a dramatic sweep of the hand, he had us all wondering whether he had taken too many walks in that odiferous wasteland. It soon became obvious to us, though, that he was in full charge of his faculties and we were operating on the very edge of our understanding. So, he asked more questions. Less expansive questions near the horizon of our understanding that guided us toward a strategy for answering the larger question. "What organisms might be living in the mud?" "How many of each kind are here?" "How large are they?" "How could we find out?"
Thus began our hands-on lesson on population sampling with hula hoops, application of physiological principles learned in the laboratory, and learning how to learn. From that day on I have enjoyed the sweet aroma of mud flats and the thrill of investigating on my own. The shift in perspective was triggered by a process that any teacher can employ: inquiry-oriented, activity- based, hands-on learning.
As the nation pursues the goal of becoming first in the world in science achievement among students (U.S. Department of Education, 1991), many are advocating an instructional approach that emphasizes activities and learning by doing. Many pushing for reform of science teaching say, "Young people can learn most readily about things that are tangible and directly accessible to their senses....With experience, they grow in their ability to understand abstract concepts, manipulate symbols, reason logically, and generalize" (Rutherford & Ahlgren, 1990, p. 186). Almost all the national reports on the conditions of teaching and learning in schools call for, "More active learning for students and less passivity; more hands-on, direct opportunities to 'make meaning'" (Schmieder & Michael-Dyer, 1991). In classrooms where students are encouraged to make meaning, they are generally involved in "developing and restructuring [their] knowledge schemes through experiences with phenomena, through exploratory talk and teacher intervention" (Driver, 1989). Indeed, research findings indicate that, "students are likely to begin to understand the natural world if they work directly with natural phenomena, using their senses to observe and using instruments to extend the power of their senses" (National Science Board, 1991, p. 27).
Instructional approaches that involve activity and direct experiences with natural phenomena have become collectively known as hands-on science, which we have defined as any educational experience that active'ly involves students in manipulating objects. Unfortunately, the use of hands-on activities is far less frequent than lecture and discussion (Weiss, 1987). Most American schools offer traditional instruction in science, with relatively few schools tailoring curricula for a hands-on approach (Howe, Blosser, Helgeson, & Warren, 1990). In a national longitudinal study, 41% of the eighth grade students were reported to be in classrooms where experiments were seldom conducted (National Science Board, 1991, p. 27). The findings perhaps reflect teachers' uncertainty, discomfort, lack of resources, or limited backgrounds with experiential approaches to science teaching, coupled with a cultivated dependency on textbooks (Morey, 1990). According to data from a 1987/88 Schools and Staffing Survey, "fewer than half of all middle school teachers of biological sciences and only about one-fifth of teachers of physical sciences felt they were teaching the subject for which they were best qualified" (National Science Board, 1991, p. 31). In short, teachers have questions and concerns about science teaching and their own teaching assignments, and many seem reluctant to engage students in "hands-on" learning.
In the pages that follow, we present ten questions that teachers frequently ask about hands-on teaching and learning, and we provide three different types of answers to each question, representing the perspectives of classroom teachers, curriculum developers, and educational researchers and theorists. The questions have come directly from teachers themselves and teacher educators, people who work regularly with classroom teachers and know the questions they ask. In an attempt to be direct and clear, we have presented the answers as discrete responses, with no attempt to force consensus or an internally consistent message. Rather, you will hear individual voices representing the broad range of teachers and specialists in science education. Responses from the research literature are necessarily abbreviated, but full citations are provided for each informational nugget. Please note that the questions are arranged in what seems like a logical sequence to the authors; they are not arranged according to any ranking or weighting process based on level of concern or priority.
Posted to the North Central Regional Educational Laboratory's
Pathways to School Improvement
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