Baird W. Lloyd
Capital University, Columbus OH 43209
James N. Spencer
Franklin and Marshall College, Lancaster PA 17604
J. Chem. Educ. 1994, 71, 206-209, copyright © 1994 ACS Division of Chemical Education, Inc.
The 1989 "Report on the NSF Disciplinary Workshops on Undergraduate Education" (1) called for the creation of Task Forces to implement broad curricular change in chemical education. These Task Forces were expected to "develop materials, especially textual and related materials, for adoption at colleges and universities and were to integrate as much as possible, both the essential elements and the exciting new frontiers of chemistry." In response to this charge, the American Chemical Society's Division on Chemical Education formed a Task Force in 1990 for the revision of the general chemistry curriculum. The goal of this group was (and is) to make recommendations for alternative general chemistry curricula; to publicize the new materials through public presentations, publications, and workshops; to provide tested support materials; and to provide workshops for instructors who wish to learn how to implement the new curricular ideas.
The Task Force has approached their charge from a multi-faceted perspective: that is, no single curriculum proposed will be adopted intact. The focus was to provide themes and patterns of directions for change along with written materials that have been tested. Individual departments may design courses from the materials that meet the needs of the populations they serve. In preparing the guidelines and materials, the Task Force was guided by the history of curricular changes in the general chemistry course along with methodologies used by groups that were able to effect curricular reform in physics, mathematics, and engineering.
At the beginning of the century the content of general chemistry was mainly descriptive inorganic chemistry. There were no unifying principles or themes on which the course was based. New discoveries, including the discovery of the neutron and the Debye-Huckel principle of strong electrolytes, gave chemists a theoretical basis on which to organize the course. General chemistry became a course focused on chemical principles. In the 1950's new high school courses provided students with a stronger math and science background, and a second revolution in the teaching of general chemistry began. The course became more complex and had an increasing dependency on mathematics. This second transformation was essentially complete by the 1970's and no major changes have occurred in the course since then (2).
Those who taught general chemistry laboratory have, since the early 1900's, been wrestling with the problem of whether laboratory time should be spent in training students to learn to use instruments and standard procedures of analysis or in having students learn how to interpret data and how to ask and answer testable scientific questions (3). This debate continues today.
In many contemporary laboratory exercises the ability of a student to reproduce known values is taken as evidence of understanding the principles involved (3). Such verification experiments follow a well-structured path and are often one-dimensional. Some innovative laboratory programs (3) seek to engage the student in scientific investigations that involve observation, data gathering, interpretation, and hypothesis formation. These less structured exercises allow varying degrees of student and teacher involvement.
The forces that caused change in the past are still at work today. The tremendous explosion in chemical knowledge and technology continuously alter the manner in which chemists do their work. At the same time, today's students are less intellectually adventurous and more.job- oriented than their predecessors. Brooks (4) offered a significant criticism of current curricular efforts for ignoring both the technology available and the issue of learner motivation. Computers have changed the way chemistry is done. Therefore, students should be taught from the beginning how to use computers to enhance and assist their learning. Allowing computers to perform the memory and computational skills would free students to perform more demanding intellectual problem solving. Brooks, also, points out the reality of motivation as a determinant of learning. Students no longer willingly perform tedious tasks without the impetus of understanding the relevance in the job at hand.
A third force that is shaping curriculum reform has its origins in our improved understanding of the processes by which students learn. Research has demonstrated the importance of actively involving students in the laboratory and lecture parts of the course. As a result, students teaching students (5, 6), cooperative learning (7), guided discovery (8), whole-class construction of knowledge (9), and teaching through (not with) demonstrations (10, 11) are examples of reforms that have been initiated in general chemistry courses. It is clear that the WAY teachers interact with students and students interact with science is undergoing a significant change.
People involved in the current efforts at reform can learn much from the experiences of those engaged in curricular reform projects of the last few years. Some of the lessons learned include the following.
In making recommendations, the Task Force uses the definition of CURRICULUM as the entire planned program of the general chemistry course. This definition encompasses the content, instructional strategies, and assessment techniques for the course. It is impossible to have successful reform with any of these pieces missing. The following represents a set of recommendations that we believe should be part of the curricular change process of general chemistry.
A recent report from the Educational Testing Service (13) gave the results of a survey of general chemistry courses at 114 college and universities that typically receive large numbers of AP students. One conclusion of the study was that the general chemistry course is crowded in the number of topics it covers, despite the oft-cited criticisms that the curriculum of introductory college chemistry attempts to cover more topics than students can be reasonably expected to learn. No single topic received adequate detailed attention. At different institutions and within each major topic, there was considerable variation in coverage. The choices of topics appeared to be those that were closely tied to the instructor's area of expertise.
Historically, course material was simplified to provide a first introduction to topics that would be encountered later by students majoring in the subject. Often, the process cut the material to a point of presenting dubious derivations or giving incorrect interpretations. The material in most texts is presented in a disjointed fashion in an effort to present everything that someone, somewhere might wish to include. It is virtually impossible to connect this material in a coherent way. Teachers of this course should give a less superficial treatment of topics, even at the expense of leaving out some of their favorite bits. The emphasis must switch from pleasing the teacher to providing a coherent, sufficiently detailed discussion of a concept or principle; a discussion that interweaves the main aspects of the principle with applications familiar enough to the student that he or she can develop an understanding of the meaning of the concept or principle. This switch in content recognizes the learning needs of the student.
Most of thermodynamics and quantum mechanics are too abstract for general chemistry. Molecular orbital treatments of bonding are, at best, limited and unnecessary. By the time MO theory is illustrated with the few diatomic examples that appear in texts, there is no further use a beginning student can make of this construct. The concept of free energy is poorly, and often incorrectly introduced in the course. Much of the chemical equilibrium simplification leaves students with faulty understanding. Any concept or principle that can not be introduced with its major characteristics intact should be left for a later course. Any concept introduced should first pass a test of "need to know for now" by students. This way, the number of concepts can be lowered without compromising the integrity of the itrodintroductoryse.
There is too much emphasis on the perceived needs of chemistry majors. An ideal course in introductory chemistry should use the principles of chemistry to rationalize experimental observations and provide a unifying theme. Students whose career paths will take them out of chemistry after the first year will take with them the principles necessary for their functioning as educated adults without having been required to learn a body of material irrelevant to them. Majors will have a more firm foundation because of the added time to assimilate deep meaning of the basic principles.
In industry and research today the basic principles of chemistry are being applied to new, complex systems in life science, materials science, and environmental science. Students should learn about these applications so they can gain insight into their future.
Two problems arise from the dependence on numerical problems as a means of demonstrating understanding in chemistry. Being able to perform a set of previously practiced steps in numerical problems is not sufficient evidence that the student understands the chemical principles involved in the situation. Students should be asked to describe and explain the principles and relationships in words.
The other problem stems from equating the development of algorithms to solve routine exercises with the building of the skills necessary to solve novel problems. Learning to use algorithms is an important part of scientific training, but science is more than learning to apply some memorized equations. In fact, research has shown that all the usual classroom techniques - having students solve exercises at the board, teacher demonstrations of how to use algorithms, having students solve countless homework exercises - do not improve the students' critical thinking skills (14).
A question is a "problem" to a student when the method of solution is not immediately apparent. "Problem" status is not an innate characteristic of the question but reflects a student's experience with that type of question. Algorithms have been developed by chemists to answer routine questions. Students who have not built algorithms for at least some of the steps in a problem will have difficulty solving the problem. With practice these students can develop patterns of thinking that can be cycled repeatedly until a satisfactory answer is obtained. The job in helping students develop these thinking patterns requires students to encounter true problems and to have the time and practice needed to develop their thinking patterns.
The student must be taught to think about the problem situation described. We often believe that students do that with the word problems that rely on mathematical calculation for solution. More likely is that they look for an algorithm and, if one is not apparent, they put it aside to have the instructor "show them how". Unfortunately, this choice robs them of the chance to develop the thinking patterns of a successful problem solver.
By similar reasoning students in laboratory should be presented with the requirement of collecting data and making sense of it, as well as of learning specific technical skills. They should do this in an atmosphere of collaboration with others. How else will they learn the processes of scientific investigation, processes that work to gain new bodies of information and understandings? Students need to learn more than the skill of matching their measurements to the numbers in the "hidden" answer book.
Since its inception, the Task Force has exchanged ideas on general chemistry with chemists from every part of the country. Many of these exchanges revolve around one or more of the following recurrent themes.
These themes reflect both the incremental and fundamental approaches to curriculum reform. Incremental changes are proposed by those who assume that certain elements of the existing goals and structure should be retained. Changes are aimed at improving the core features of the curriculum. Those who argue for fundamental change seek to alter the very essence of the curriculum. They seek new goals and structures that transform familiar ways of presenting information into truly novel soluisolutionsersistent problems.
The Task Force has initiated three approaches to curriculum reform at the national level:
(1) a core/modular approach, (2) a zero-base curriculum, and (3) a laboratory-centered curriculum.
These curricula incorporate as many of the previously reached conclusions of the Task Force as possible.
This approach assumes that there is a basic set of concepts that every student who takes general chemistry should know. Once this core has been defined, it can be supplemented with modular material that meets the needs of the individual instructor and the students enrolled in a particular section of general chemistry. The philosophy of this approach is that students do not need to be introduced to every area of chemistry at a superficial level. A firm foundation would be established with the core material, supplemented by a deeper study of specific topics chosen by the instructor.
The zero-base approach assumes that the problem of identifying what should be taught in general chemistry is best answered by examining subjects of importance to non-chemists that require a substantial knowledge of chemistry. The next step involves an analysis of the theoretical principles necessary to achieve this understanding. This analysis should determine which of these principles should remain in the general chemistry course, what additional principles should be added, and which of the currently taught theory should be removed. The net result would be a curriculum based neither on history nor custom, but on demonstrated need.
The goal of the zero-based approach is a detailed curriculum in which relevant topics are developed to the point that students understand the phenomena being discussed. By empirically determining what chemical theory is needed in the introductory course, and then introducing this theory as needed - and when needed - it should be possible to turn chemistry into a more stimulating subject.
The laboratory-centered instruction project utilizes inquiry laboratory projects, designed to engage students in scientific methods of investigation. These projects require data gathering and analysis, hypothesis formation and testing. Concepts introduced through laboratory activities are then brought to the classroom for discussion and application. This new approach is a significant change from standard practice in which the laboratory is used to confirm the validity of concepts introduced in lecture. The instructor is no longer an authority figure who acts as the sole source of information, but a facilitator who assists the students in discovering the concepts for themselves.
In order to help instructors implement the recommendations the task Force is preparing for publication in Summer 1994, a monograph that will include a collection of articles written by members of the Task Force, descriptions of a core-modular curriculum and a laboratory centered curriculum, and a proposal for setting up a zero-based curriculum. Also planned for inclusion will be sections on current innovative curricula, novel ways of teaching traditraditionalcs, and suggestions for incorporating real problems into homework and assessment procedures.
The Task Force will continue to sponsor symposia at the national ACS meetings, regional and local meetings. Task Force members will continue the policy of holding seminars and discussing the Task Force findings at various venues across the country. We encourage, criticism and suggestions from all members of the chemistry community.