SPRING 2006 WORKSHOPS
"FOUNDATIONS OF SCIENCE: A Lab Course for Nonscience Majors"
(Originally published in More History & Philosophy of Science in
Science Teaching, Proceedings of the First International
Conference, Science Education and Department of Philosophy,
Florida State University, Tallahassee, Florida 1990 311-352)
Department of Biological Sciences
Hunter College of The City University of New York
695 Park Avenue, New York, N.Y. 10021
ABSTRACT (View entire document as PDF file- Download here... )
This paper describes a multidisciplinary introductory science course for nonscience majors developed at Hunter College . This course is nonstandard in a number of its features: (a) It follows a small number of major themes from a predominantly historical point of view to develop the idea that science is a process of obtaining knowledge about the world; it does not attempt either to survey the major conclusions of science or to focus on significant recent accomplishments. (b) It includes a laboratory as an integral part of the course. The lab experiences are designed to enable the student to explore and discover phenomena as well as to become familiar with the procedures of designing experiments to test hypotheses; they are not intended simply to measure constants or confirm known results. Related sequences of labs are used to develop more complicated concepts and to show that explanatory models often derive their significance as they can generally account for unrelated phenomenological laws. The labs are also used to introduce students to the quantitative aspects of the course in terms of data analysis and interpretation. (c) Finally, writing is used both as a means of learning and of assessment. Frequent essays integrating all aspects of the course are returned to the students for revision prior to grading. Two appendices present a detailed syllabus for the course and a discussion of the way the lab component fulfills the educational objectives.
Several years ago, acknowledging the problems science "illiteracy" poses for both the individual and society, Hunter College embarked on a thorough reconsideration of the role of science in its distribution requirement. The result of a Foundation-supported study, by representatives of the social sciences and humanities as well as the natural sciences, was the recommendation that Hunter students participate in a three tier experience in science that would span their entire stay at the college. This would include an introductory one year lab course in "Concepts of Science", a choice from second level "science in depth" courses which would be departmentally organized, and a capstone relational course. This latter would be selected from among a variety that could in principle originate from almost any department in the college.
Major features of this proposal are that by working at several levels it more likely makes science a part of the student's developing intellectual view, it includes approaches to science from different perspectives, it presents science to the relatively mature student as well as the novice, and in its final tier it demonstrates that science really was connected to many disciplines.
Goals and Rationale
The primary goal of the first course in this program is to provide the nonscience major with an introduction that leads to the appreciation of science, and facilitates its understanding. This introduction emphasizes the nature of scientific reasoning and includes illustrations of the scope of the material, the nature of scientific questions (and answers), the similarities and differences in the approaches to questions raised in the different areas, and the common features which tie many of these areas together. When considered in the context of these different areas, "science" is defined both by its methodology (involving an approach to "truth" that is continually subject to revision, and is thus "self-correcting") and its subject matter (the study of the "outside world"). This course is conceived as the beginning of the students' formal experience with science; it is expected that upon completion of this course they will take at least one subsequent course that will involve studying "science in depth". In this introduction students are presented with the major areas (disciplines) of science, some major conclusions, the ways in which these have been reached, and to a limited extent the consideration of why some questions are pursued while others are ignored and/or abandoned. In some areas this ultimately requires the ability to follow a quantitative train of thought, and to outline calculations necessary to answer critical questions.
Because today science is assumed to deal with an outside world, the course has as an integral part "laboratory" periods devoted to extending the students' experience and providing an understanding of how nature and natural phenomena can be critically observed, measured, analyzed, and tested. That is, the roles of appealing to nature to define the nature and limits of scientific inquiry and to test the validity of predictions which follow as necessary conclusions of proposed explanatory models are explored.
An additional goal is that students learn to see science as a human activity that, in part, deals with the variety of problems that society faces as it interacts with (manipulates?) its environment. While this is not a course in the philosophy of science as such, the philosophical foundations which govern scientific practice are highlighted, especially as they distinguish science from other human endeavors. Beyond that, the relationship of science to social and industrial needs and the technology of a given period are indicated by appropriate references throughout the course.
Since our target population consists of students who are not only unfamiliar with basic science, but are often hostile to it, we make no assumptions about prior levels of accomplishment. Unlike such areas of the curriculum as language and arithmetic where there is a generally agreed upon high school coverage, the lack of which can be provided in "remedial" courses, we must really be in the position of starting from scratch. In Piagetian terms, this population has been described as being nonformal operational; they are not (yet?) ready to use or follow abstract reasoning. Assuming that cognitive skills can be developed, we have accepted as a part of our job that task of providing our students with extensive work in developing the reasoning skills that are prerequisite to understanding science.
Nevertheless, our students are not devoid of experience with an outside world. Because of today's mass media many of them have in fact vicariously experienced situations to be found only in the wildest imaginations of generations past. But their approach to these phenomena is usually not scientific by today's standards.
In fact, they are typical of what has been increasingly accepted among cognitive scientists, psychologists and educators; they approach these experiences with the outside world with what we would call the "wrong" ideas of how it works. Ultimately, if learning is to take place, there must be a process of "concept modification". However, until explicitly confronted with an inability to "explain" their experiences in terms of their concepts, most people simply misinterpret these experiences in terms of their preconceptions. They do not, in the classic phrase, "save the phenomena"; rather, they save the (wrong) concept. (Thus a three year old explains his motion in a swing "because of the wind", which he feels when and only when he is swinging, and denies his mother's role in his motion.) In point of fact, even such confrontation does not always lead to concept modification; the desire for generality and consistency which may be a prerequisite is not part of the world view that our students bring to the classroom. Their view includes many preconceptions which have been characterized as "Aristotelian", and it has been suggested that the barriers that they have to overcome are much the same as those confronting the developers of our modern scientific world view in the revolutionary periods of the 16th through the 18th centuries.
This means that we cannot base our presentation on formal or abstract considerations, even if those are what we rightly see as being the crowning points of our disciplines and pinnacles of human achievement. While they may, in fact, be the counterparts of a Shakespeare tragedy or a Bach fugue, they do not have the surface accessibility that these works do.
Nor can we accept the learning of abstract calculating and problem-solving skills as a major goal of the course, even if they are fundamental to scientific activity. Many students cannot master these in the time we have at our disposal (we do not address the question of whether they can ever master them). The best we can hope for in a general education course is that all students can follow some arguments, and describe others. To the extent that the key to science literacy--and hence, to scramble a metaphor, the stumbling block in its absence-- is the ability to use proportional reasoning, this has to be developed before we casually apply it. We have designed our course to do this in context, but not to make it an introductory end in itself.
Equally fundamental and related, but not so well documented, is the need to make sure that our students are able to follow the language of our reasoning processes; many of our students don't really know what "because" means (or, perhaps, what we mean by "because"). And others (or some of the same ones) also have difficulty appreciating the full significance of words signifying sequential sets of events. Again, simply giving a dictionary definition won't help. We have also made sure, not only at the beginning but throughout the course, that we go over our reasoning processes and justify them.
Finally, just as many of our students are "innumerate" when they enter college, so too, their assimilation of their media experience lacks more than a nonscientific approach. Despite a moderately sophisticated vocabulary, they often do not know what concepts are referred to by these words. And by "concept" we mean the accumulation of experiences that demands the use of a new word. Thus "electron" is more than "a point charge". Even if the concepts of point and charge are assumed, we believe that they apply to electrons (or, perhaps more properly, that the word electron should be introduced) because of the outcomes of a variety of experiments. And these, in turn, must also be spelled out in detail. Our English-teaching colleagues have used the phrase "to unpack" in the sense that terse explication must be opened up and spread out before the novice. We try to do the same thing. But not casually, in an "as we come to concepts we'll explain them" manner. The course has been designed to do this. In part this means that all fundamental concepts have had to be developed in a sequential manner. And in part, because we have seen that, for example, many of our students have demonstrated an inability to deal with concepts of volume which we had thought were part of previous learning, we have to be very clear about the structure of our arguments.
Our way of avoiding the trap of jumping in too soon has been to adopt a (modified) historical approach. This makes sure that concepts are developed in a proper sequence. At the same time it does not mean that we have to adhere so closely to history that all the mistakes and dead ends--let alone all the paths leading to "correct" generalizations--have to be followed. We have been selective so that we get to our desired end(s) in a rational manner, developing new concepts as needed on the basis of exploring the implications of both previous notions and the interpretations of new experiences. Not only does this make sure that the students are given the background that they need at each step; it also illustrates the dynamic and evolutionary nature of science.
Foundations of Science
The first phase of implementing this plan has been the creation of a new course called Foundations of Science. It is the introductory course in the sequence outlined above, and is the result of extensive committee work and discussion.
The initial syllabus for this course was "content driven" in the sense that we tried to include "all" significant conclusions and major contributions from the standard disciplines. While the result had surface appeal to experts, it was clearly unteachable. A panel of expert scientist-teachers was enlisted to assist us in its revision. Their written comments and the ensuing discussion convinced us what we knew but had tried to ignore: the beginning student of science has to be introduced to the subject in ways that differ significantly from the traditionally accepted modes of instruction. We readily agreed that trying to structure our course around a summary of current content was not the way to succeed. As an alternative we reduced the scope of our coverage, and decided to take a historical approach to whatever we included. As mentioned above, this ensured that relevant concepts were introduced in a proper sequence, that there was time for full explanations, and that these were not simply logical or verbal manipulations of meaningless phrases.
We further decided that beyond the flow of history our students needed to be introduced to what has become characteristic of all science. We conceived this major feature of the sciences to be the way scientists think, the way they identify and approach problems, and the way in which the results of these
efforts are reflected in the science of a given time. As our planning proceeded, we realized that such generalizations as "thinking" and "an approach to problems" can only be reasonably discussed in the context of some part of science itself.
Not surprisingly, we concluded that the science whose study most appropriately supports the appreciation of the scientific approach is the science that gave birth to that approach. This science can be found in the three themes which form the skeleton of the course. Indeed, all are critical to what may be called the scientific view of the world today, a fact which justifies the title of the course. These themes are: (a) The development of the idea of a solar system, the so-called heliocentric (sun-centered) system of the planets, and the inseparable study of motion on earth. Despite appearances, the sun (unlike the moon) does not go around the earth. (b) The long and difficult process of realizing that matter -- the stuff of the universe -- is fundamentally particulate in nature, and the properties of matter can, in part, be understood by understanding the properties of these particles. As some ancient philosophers thought, there are indeed "smallest pieces" of the many kinds of matter we see; their explanations of the properties of matter, however, have not passed the tests of time. And (c) the manner in which it was recognized and accepted that the earth, and life on earth, are not as unchanging as they seem, but have a history. The metaphor of "the sands of time" refers to more than the contents of a hourglass. In brief, these themes may be summarized as the heliocentric theory, the atomic theory, and the theory of evolution.
Let there be no mistake about it: while we have given up the idea of covering a traditional curriculum, we have by no means opted to abandon all content. Quite the contrary. For each theme that we have adopted there is a story which we want to tell, and this is our content. Briefly, each of these themes is developed from its origins in prescientific experience through the process of concept formation and modification to the point where the modern concepts have emerged. In the summary which follows, the names of prominent contributors to these stories have been used as shorthand for their contributions.
For (a) the story takes us from the astronomical observations of the Babylonians through the speculative cosmology of the Greek natural philosophers, the medieval critics of Aristotle to the revolutionaries of the 16th and 17th centuries: Copernicus, Kepler, Galileo, Descartes, Huygens, and Newton. Our approach has two concerns: the developing models of the heavens and the emerging science of mechanics--the study of motion. The latter, in turn, is significant because of both its specific conclusions and the new approach introduced by Galileo for its study. We conclude with the rudimentary ideas of energy and its conservation. What emerges from our telling of this story is that, revolutionary as many of the participants may have been, each was in many ways extremely dependent on the contributions and partial successes of his predecessors/contemporaries. Thus "Newton's First Law" is shown to be a simple translation of Descartes' modification of an insight of Galileo's, his "Second Law" is shown to be much the same as a principle earlier enunciated by Huygens, and his Law of Gravity, in its simple form, is seen to be identical to a finding of Hooke. At the same time, Newton's contributions are themselves revolutionary. His concept of "absolute, true, and mathematical time" as flowing "equably without relation to anything external" is specifically counter to the then prevailing fact that each town had its own clock which tolled its own time, and the Catholic church's use of canonical hours, twelve per day throughout the year, which changed their length to accommodate the seasonal variations of daylight.
For (b) we find the roots of our study in the speculations of the Greeks, the variety of technological and craft knowledge (e.g., metallurgy, glass making, perfumery, medicine) exploited in the prescientific ages, and the alchemical beliefs and practices of the Arabs and other Mediterranean peoples. We then pursue the Galilean approach to experimentation and "the mathematization of matter", especially as it related to determining the properties of air in the 17th century (Torricelli, von Guericke, Boyle), and follow this with the work of the "pneumatic chemists" (Black, Priestly, Cavendish, Lavoisier) of the 18th century. The fact that both of these approaches can be accounted for by the existence of particles brings us to the atomic theory of Dalton, Avogadro, and Cannizzaro, and periodic table of Mendeleyev. Finally, the combining properties of atoms is also shown to lead to the "explanation" of the properties of larger aggregates (molecules), particularly the macromolecules that form the fundamental structural units of life. While in the first theme there is an almost linear development of concepts, in this theme it becomes apparent that the more successful models are those that are more general in that they are able to account for an ever increasing number of phenomenological laws. The kinetic theory of matter, for example, is not accepted because of its relationship to one phenomenon, but to many.
The third theme (c) also begins with a survey of primitive accounts, in this case of the diversity of life and geological forms. It is shown that attempts to improve upon early ideas depended largely on ideas of classification (Ray, Linnaeus), and were as severely limited by philosophical/religious ideas as they were by lack of information. The contrasting notions of geological "evolution" (Werner, Hutton) are studied as an example of opposing paradigms, and the interaction of the studies of biology and geology (Buffon, Cuvier) is followed with the work of Lyell and Darwin leading to the latter's ideas of natural selection as a mechanism for evolution. The range of speculative accounts for diversity (represented by the works of Paley and Chambers) which preceded the period of extended observation is also considered. The various interpretations and philosophical uses (and misuses) made of Darwin's theory are discussed, and we conclude wit the "new synthesis" (the "explanation" of evolution in terms of the biological processes relating to genetics), a nod to molecular genetics as a means of unifying this developing idea of history with the current knowledge of the physical world, and the recent revolution in geology dealing with plate tectonics.
The conclusions of all of these themes share three properties: they all refer to a world outside of and beyond our immediate experiences; they all illustrate the process by which scientific understanding is achieved; and they all run counter to our immediate perceptions and naive interpretations. At the same time, each theme tells us something different about this outside world: it is subject to mathematically precise laws; it has an invisible structure that is not, like a peeled onion, simply "the same only smaller"; and, over periods of time that are unimaginably long, it has changed dramatically in the process of assuming its current state. The Foundations of Science goes from the beginnings of science to an understanding of these conclusions. In this process we show how and why science developed the way it did, and at times how this history has been related to other aspects of the history of human activities and achievements.
Fleshing out our course on these skeletal story lines immediately gives a contextual relevance to each subtheme that we explore. With little effort it is clear that the subject of each part of the course has a reason for its inclusion as it develops an area opened up earlier, or answers questions that have been posed. But it is also clear that there were serious limits to how far we could go in this manner. It is unreasonable to expect our novice students to exceed the demands made of beginning majors so that they can go from primitive knowledge to current events. Granted the recent advances are compelling, but understanding them in more than a surface manner demands more time than can be devoted to each in a year. Besides, as we continually reminded each other, this course was the foundations course; there would be more time in subsequent courses to bring students up to the present. Thus each of the themes mentioned above turned out to have two components: the first, which was more rigorous, traced the development of critical ideas; the second, somewhat more descriptive, sketched some more recent developments. While we mention atomic structure, genetic engineering, and plate tectonics we make no claim to having presented students with more than an inkling of the justifications for the knowledge growing out of these areas of research.
Although in following the development of concepts we are taking an essentially historical approach, this should not be confused with a "history of science" course. Our concern with science as a process -- as opposed to simply a collection of facts or conclusions -- has led us to realize that this can best be appreciated if the process is studied, and studied repeatedly. By following each of our themes, or story lines, in detail, little is left for the student to misunderstand because she has been asked to guess what the reasoning patterns were, or what facts demanded conceptual changes or why.
Reading, Lectures, and Listening
So much for the content of the course. Learning, on the other hand, requires the student's engagement in four activities, all intended to result in thinking: reading, listening, doing, and writing. We have had great difficulty locating appropriate reading material. Our attempts at finding "selections" have often resulted in far too many pages, still leaving far too many gaps in what we consider appropriate coverage. With this as starters, it is not surprising that students often find the reading assignments obscure. At the same time, many of our students have been unable to read "variations on a theme", that is, two different approaches to the same material, each presenting a slightly different emphasis. An alternative, preparing our own text, has been tried by Professor Bennick (Physics) who has had major responsibility for developing the first story line. Student response to his material is very positive. The goal and achievement of his endeavor has been the frequent presentation of major advances in remarkably comprehensible form. For example, while most of us identify the significant achievement of Copernicus as the removal of the center of the planetary system from the earth to the sun, few of us are aware that this simple device permitted the determination of the relative size and order of the planetary orbits. The actual calculation requires only simple geometry, but it is not included in most texts on this subject. With other calculations of this sort the role of geometry in understanding the heavens is illustrated as well as the unifying role of what we call the Copernican revolution.
Listening occurs in the lecture hall. In fact we hope that this results in understanding. Unfortunately, many students, and probably a majority of freshmen, don't know how to "listen with a pencil". In our first year we had several lecturers, with as many different styles of lecturing. We rediscovered that students will write down what is written for them on a board or screen, but that they are at a loss to abstract as they listen. We had lectures that were filled with relevant illustrative slides that students couldn't summarize. And we had lectures punctuated with appropriate demonstrations. The latter were well received, but not immediately understood. They were viewed more as the magic which may have been their ancestors than as phenomena which are related to each other by the logic of scientific understanding. Professor Lavallee (Chemistry) has exploited a number of these to make points, often explosively. Only at Professor Duschl's (Curriculum and Teaching) urging did we finally realize that students needed at least lists of names of these, and better yet brief summaries of their conclusions. The point of this is that serious consideration has to be given to ways in which the students can be made active participants in the learning process, even as the presentation of material is more or less traditional. Just as the story lines of the course are thought of as skeletons to which the content is attached, so the lectures must be seen as only part of an "information delivery system" which includes the activities of laboratory experiences and writing as well. In these latter, of course, the student can in no possible way be passive, but must become an active agent in his own learning.
Observing and Doing
One major conclusion that has found its way into the modern scientific world view is that there is an outside world susceptible to objective observation, in sense that "yours" are as good as "mine". However, not all observations can easily be described in words, or even in pictures. Before we can master the language that refers to the world, we have to become familiar with the "things" that the language refers to. Some of these things are phenomena, or events that recur under standard or controlled conditions. Others are processes, or ways in which they occur. And still others are real "things" such as rocks and bones and flowers and mysterious white powders. The development of science follows the study of these various phenomena, processes, and things, and the place where these are studied is the laboratory. The study itself involves the act of doing.
The goals of this course would be ill-served were we simply to follow cookbook procedures. Rather, we view the lab as an opportunity to come face-to-face with part of the real world. The labs are implicitly based on what has been called a "learning cycle" approach. In this, the student explores, analyses, and applies. In short, the labs are the places where students find out what the substances and problems are that have confronted scientists, and have become the bases of science. In the first instance this approach enables the student to identify what is to be studied further in the sense that "that, there" can be specified even before it is named. Next, after naming it, "that, there" can be studied to find out what can reasonably be inferred from it, what it is, how it is held together, how its workings can be described, and, if possible, how they can be explained. These are the activities of scientists, this is the process of science, and by providing the opportunity for doing we are better able to convey--more fully than we could if we were limited to words--what the nature of science is.
As we worked on the labs, our skeptical colleagues frequently asked "What would be done in a lab for nonmajors that would be better than what was usually done?" These are some of the answers: a full detailed discussion of the lab exercises and their relationship to the goals of the course and our view of the students' learning process is presented in Appendix II.
We have given students lenses to play with, and with minimal direction at the end of three hours they had constructed telescopes. We started a lab on indirect measurement--critical for understanding the way in which a scale was placed on the heavens--with paper triangles so that we could be sure that students really knew what similar triangles were, and what properties they had; by the end of the lab the students were determining distances across the street. We repeated Galileo's experiments with rolling balls and, true to our self-imposed restrictions, we insisted that we use the time measuring technology available to him as well. This meant weighing water, the technique of the water clock. His reported accuracy -- "one tenth of a pulse beat" ‑‑ was reproducible, and more than adequate for reasonable quantitative results in a late twentieth century laboratory. (In fact, the limitations on accuracy are due to human physiological reaction time, not technology.) In this way we not only do science, but we show that while progress may in many instances be limited by technology, in many others it is the lack of a concept that is limiting. The Greeks had the technology to discover Galileo's laws of motion, they lacked the freedom of the mind.
To reinforce the concepts that Galileo's experiments were so instrumental in establishing, we go on to repeat the experiment with 20th century technology. In this case we use an air track coupled with a sparking device. The air track suspends a glider on a cushion of air so that it is essentially frictionless, and the spark provides a time measure accurate to hundredths of a second. The results are of course much the same as those Galileo (and we) obtained with a rolling ball, but the students are shown that there is more than one way to skin a cat. At the same time they are prepared to use the modern instrument to study Newton's second law and the conservation of energy. We also use these labs to demonstrate projectile motion on an air table which provides a frictionless plane on which a puck can slide. This, too, is conceptually similar to an apparatus described by Galileo, but rather than use approximate measurements of position we videotape the trajectory of a projectile and use a frame‑by‑frame analysis to show that horizontal motion is uniform, while vertical motion independent and is uniformly accelerated.
In other labs, as we modified what was traditionally done by freshman to make concepts more apparent, we have developed approaches that will find their way back into the major's courses. This was particularly the case where the liberation of "fixed air" (carbon dioxide) from sodium bicarbonate (baking soda) by mild acetic acid (vinegar) was studied. The traditional approach has been to use an "indicator" (such as litmus) which changes color to tell when a reaction had reached completion. The mechanism of such an approach is extremely hard to get across to beginning students, and questionably worth the time and effort if it is not likely to be exploited in future labs. Our solution was to use the equally time‑honored approach of letting the reaction go to completion by adding vinegar until no more gas is liberated. This particular lab is in the midst of a sequence which starts with a simple exploration of the relationship between the volume and "pressure" of the gas contained in a stoppered syringe, and goes on to experiments in which it is shown that the relative "particle weights" of magnesium and calcium are 25 and 40, in excellent agreement with currently accepted values for atomic weights. The fact that students find these numbers emerging from their own work, goes a long way towards making the abstractions of the invisible world real to them. We attribute a major part of our success to the process of developing groups of laboratory exercises in which related concepts are developed sequentially, but in digestible portions. We feel that this, coupled with the historical approach which we follow in lab as well as lecture, is critical for the instruction of novice nonscience majors.
In the third part of the course we start the study of diversity by asking students to classify a variety of materials without the benefit of direction or a "key". This shows students the scope of the problem in two ways, by introducing them to the extent of diversity and to the very real problems that exist in trying to talk about this diversity. We have them mimic the process of selection to show that different phenotypes (colors of clips or bits of paper) can actually confer a selective advantage in different environments (patterned backgrounds). We discuss genetics as a mechanism for maintaining diversity, and use this as the occasion to explore the concepts of populations and statistics. We have also introduced a subtheme
into this set of labs covering the idea that a particular kind of substance, DNA, is the material basis of genetic transmission. While it is possible to recreate the critical experiments in the course of one hectic lab session, it is clear to us that our students would retain relatively little. Our approach, then, as described above, is to break the story into a set of about half a dozen distinct concepts that will be presented sequentially in roughly 20 minute segments of labs. This extends the entire exercise over a period of several weeks, and at each stage provides time for the students to assimilate what has been done, and to see why more has to follow.
Having thrown out the cook book, our approach is to engage the students in the process of discovery by confronting them with raw materials, or with problems. Group discussions are used to encourage the class to propose and criticize their own approaches to answers. Since time is precious these discussions and subsequent activities are frequently guided by the instructors, but they are not lectures. "Wrong" approaches can often be quickly dispensed with by examining them in the light of class experience. The result is a mix of observation, talk, analysis, planning and action.
When possible, this leads to the collection of data. This becomes the occasion of yet another unusual feature of the labs of this course; they are the places where the numerical and mathematical aspects of the subject are met head‑on. Thus students are introduced to data organization and analysis ‑‑ the techniques involved in tabulating, averaging, graphing and inferring algebraic form ‑‑ in the laboratory where the data are obtained. Since so many of our students needed remedial work before they entered this course we feel that this approach is the only fair one to follow. The mathematical skills which these students should now have are still only tools to be used under supervision in conjunction with the analysis of the scientific context in which they must be applied.
In sum, then, the laboratories are the places where the "objective" world of things, events and processes is encountered, explored, and to a limited extent mastered. The subjects of the labs are selected to complement the material that is covered in lecture and reading. The techniques of handling things (both the objects of study, and the tools used to study them) and analyzing data in the lab provide take‑home lessons that cannot reasonably be expected to grow from more limited cerebral exposure.
Thinking and Writing
Yet another of the significant ways in which this course differs from other science courses is its emphasis on writing. This is because we strongly believe that a major part of appreciating the approach of science is the ability to "follow an argument", that is, to follow the reasoning processes that have led to some of the major advances of science. This skill will be crucial to understanding current and future advances as well. But this is not a skill that can be acquired simply by listening, or by reading; like other skills it must be practiced. In this course, the practice of finding numerical solutions for certain types of problems is pursued in the labs. Outside the labs the honing of critical thinking abilities is in the form of considering and writing answers to different types of questions.
In fact, we require several short papers, all in response to specific questions distributed during the term. As the course progresses these require the student to describe, explain, discuss, analyze, etc. specific points that have been covered in the reading assignments, lectures or labs, or to make comparisons between or among different approaches. The essay questions ask the students to write. As preparation for this there are more frequently distributed "focus questions" which direct the students to the sub‑themes that run through all aspects of the course. The goals of both the essay and focus questions reflect a variety of ways of knowing. Thus we start by asking students to "describe" so that they become familiar with the problems of precision in observation and communication, but not burdened by the difficulties that may be inherent in "explaining" or "analyzing". This approach probably follows the individual's intellectual development as well as that of any of the sciences; one must be familiar with what one is studying before one embarks on a more abstract task.
Both focus questions and essays give us the opportunity to leave the linear approach that is required by any given text or set of lectures. In this sense we take the opportunity to explore such concepts as that of a "model" in science, or the notion of "schools of thought". The use of models is pervasive through all of science, although the use of the term may be relatively recent. The idea of schools of thought appears to be obvious, but in fact many of our students are not familiar with the fact that there may really exist contending approaches to ‑‑ or interpretations of ‑‑ a body of experience. It is often only in retrospect that these points can be made, and we do this with the focus questions.
The essence of this graded approach to understanding may be seen by the directive words that are used in our essay assignments. The first essay asks students to "state ... identify ... describe," the second requires them to "identify ... summarize ... present the reasoning," and the third says "discuss the contributions [of two of three men] relating them to each other." The fourth paper was a lab report which requires that the results of several labs be integrated, and the evidence accumulated (observations) be related to the conclusions. Since these labs accompanied several weeks of lecture and reading, we expected the understanding of all three areas to be integrated. Specifically, we are not looking for particular graphs or numbers.
The last essay in the first semester makes demands of students that reflect our expectations of appreciation of fact and broad comprehension of the synthetic processes of science. We start by naming four scientists who worked on the same problem. We then ask students to "A. Briefly characterize the approaches used by each and compare any two... B. Using four examples... show how [a particular] model could account for the observations. C. What [in your experience] is not adequately addressed by this model?"
A significant part of the course grade is based on these essays and written parts of exams. But we do not simply grade "answers". Instead, we return initial drafts with comments so that they may be revised and resubmitted for grades. (As an administrative aside, grading is performed by a selected group of graduate student lab instructors. They are generally instructed in the criteria to use, and we have weekly course meetings which cover lab preparation and general course management issues such as grading. We find no problems with this procedure, but it should be noted that these instructors are paid for the grading and course preparation in addition to their regular lab instruction wages. This is not a cheap means of teaching.) In practice we have noted that some students do not resubmit their essays, and others simply correct or modify their first drafts as indicated. Neither of these responses is what we planned, although the latter probably does have some effect. In many cases, however, we have noted significant improvement of revised essays compared to first drafts, as well as improvement in first drafts submitted at the end of the semester compared to those submitted at the beginning. These are both the effects we had hoped for, indicating that understanding can be achieved through the process of writing, and that the process of understanding can also apparently be effected by continued guided practice.
Those of us involved in the development of course have all experienced an unexpected degree of excitement with the project, and achieved valuable insights, even into our own specialties. Informal student responses have, as one may imagine, run the gamut of pan to rave. Reactions to questions, labs and demonstrations have justified our intuitions in gauging the level that was appropriate to our student population. Lab results have also gratified us in that students have been able to obtain good data and sound conclusions without the benefit of prior training. And the choice of writing as a means of evaluation of student work has also proved to be appropriate. Those students who choose to use the revision option as a means of improving their writing skills present us with final products on essays and on exams which show that they are not only are performing excellently, but have improved during the term.
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