Strategies for Assisting Students Overcome Their Misconceptions in High School Physics.
November 30, 2000
Abstract
Misconceptions are a troubling issue for teachers and students in high school science. This is especially true in physics due to its often abstract nature. Students arrive in the physics classroom with preconceptions and a short lifetime of experience that is often contradictory to accepted physics thinking. Such a combination usually leads to some problems for students of various abilities. These problems can be complicated by even by well meaning and competent teachers. This paper examines the nature of misconceptions, their sources, suggested methods of identifying and confronting misconceptions in high school physics as well as strategies for overcoming students misunderstandings. The framework of the paper consists of topics commonly included in introductory physics.
Technology is being integrated into science education in myriad ways. Microcomputer based labs and simulations are just two of the newer uses of technology. The use of technology has much promise as a tool for remediation of students' misconceptions in physics. While there is a constructivist backdrop to the entire paper, this philosophy is most discernable in the sections regarding technology.
Introduction
While student misunderstandings across the curriculum is a very popular topic in staff rooms as well as in more academic settings, science teachers especially have many unanswered questions about misconceptions. What is a misconception? Is it merely a misunderstanding? Is a misconception different from a preconception? How does a student develop misconceptions and how can teachers help students confront and overcome their misconceptions? Are there different types of misconceptions and does the high school teacher need to know all of these answers to be an effective teacher? This paper will focus on answering the question "how can teachers help students overcome their misconceptions?" For the purposes of this paper, I will focus on the teaching of mechanics in an introductory high school physics course. This will answer many of the questions listed above with examples from the student misconceptions literature.
A widely accepted perspective on the nature of learning is that it is a process of conceptual change (Kyle, Family & Shymansky, 1989; Linder, 1993). Learning is a process in which a student changes conceptions through capturing new ideas and knowledge and replacing the old with the new (Hewson & Hewson, 1991). Conceptual change is an individualistic process as it occurs at different rates (Eckstein & Shemesh, 1993). Scott, Asoko and Driver (1991) defined learning as conceptual development as opposed to a piecemeal accretion of new information. Similarly, Tao and Gunstone (1999) spoke of the conceptual change as microcomputer-based laboratories conceptual addition. Conceptual change or in other words, learning is achieved by the following: acquisition of new information, reorganizing existing knowledge (Dykstra, Boyle & Monarch, 1992; Linder, 1993). What then is a conception? A common definition would describe a conception as characterizations of categories of description reflecting person-world relationships (Linder, 1993; Kleugel, 1999). A conception is our understanding of a particular part of our natural worldview (Kyle, Family & Shymansky, 1989). Linder (1993) explained conception as having both a structure (a how attribute) and a meaning (a what attribute). For example we need to understand what we believe an atom to be (the what attribute) as well as its behaviour (the how attribute). How well a person conceives or comprehends a concept or idea in physics depends on the meaning they assign to the information as well as how they organize their knowledge of that particular domain (Linder, 1993).
Students can have misconceptions about scientific facts, models, laws and theories (Brown and Clement, 1987). Misconceptions have a variety of labels in the research literature such as alternative conceptions, alternative frameworks, naïve conceptions, intuitive or spontaneous concepts or alternative interpretations (Linder, 1993; Mestre & Touger, 1989; Moreira, 1987; Tobias, 1987). Such misconceptions are an important part of children's culture and a significant component of children's science (Renner, Abraham, Grzybowski & Marek, 1990). Terry, Jones and Hurford (1985) found that misconceptions could occur in a student's understanding of the scientific method, or in the manner in which scientific knowledge is organized (Committee on Undergraduate Education, 1996; Hammer, 1989). Consider the following; if a student's learning of a particular concept is dependent upon a lab exercise based on expertise prior to that student's mastery of the scientific process (or method) then obviously the learning process can be seriously hindered (Linder, 1993). Gordon (1996) reminds us that if the structure of the knowledge to be learned cannot be aligned to the existing structures within the learner's knowledge then there cannot be assimilation of the new knowledge.
Much of the conceptual change literature is built upon the Piagetian concepts of assimilation, accommodation and to a lesser degree cognitive dis-equilibrium. Assimilation is commonly used as the process whereby the learner is able to gain new knowledge by fitting new information into existing knowledge structures or schema (Tao & Gunstone, 1999). Accommodation however, requires changes in structure before the new information can become part of the learner's knowledge or in other words a change in conception (Dykstra, Boyle & Monarch, 1992; Posner, Strike, Hewson & Gertzog, 1982; Tao & Gunstone, 1999). For accommodation to occur usually the learner enters a state of cognitive ids-equilibrium where the learner encounters information or an event that does not fit with existing beliefs (Dykstra, Boyle & Monarch, 1992; Posner, Strike, Hewson & Gertzog, 1982).
Our provincial curriculum is structured as a spiral or as some would say an iterative cycle where concepts are introduced in the primary grades, expanded upon in middle school and refined in high school. Unfortunately there are years between these iterations of introduction, expansion and refinement, which permits plenty of time for confusion to enter the learner's knowledge. Schoolyard and backyard interpretations of classroom experience are often not, what was intended by the instructor (Kyle, Family & Shymansky, 1989). There are many types of misconceptions originating from diverse sources to confuse high school students. Fortunately, there are many student-centered approaches to challenging and overcoming such problems, some of which are innovative methodologies involving computer technologies.
Research Question
How can high school teachers help physics students overcome their misconceptions?
Rationale
This topic is at the heart of the teaching and learning process; students need to understand the science content as best, they can in order to make sense of their natural world. Helping students overcome any misconceptions they may have can only expedite this process. This document reviews research literature regarding misconceptions in introductory physics focusing on their identity, sources and methods for correction especially within the realm of technology. The discussion explicitly examines the implications that the research has on the teaching learning process. Particular to this discussion is the focus on providing the high school science teacher with strategies to improve learning through confronting and challenging the students' misconceptions.
This project is intended to be primarily of interest to high school physics teachers and secondly to those within the Science Education Faculties. While this is an original work, based upon the research literature of others, it has been filtered through my 15 years of science teaching experience, and the influences of three disparate university degree programs.
Literature Review
There is now a quarter of a century's worth of good research literature on misconceptions in high school science available (Schultz, Murray, Clement & Brown, 1987; Scott, Asoko & Driver, 1991, Tao & Gunstone, 1999). There is a thorough sampling of this literature presented within this document, especially with respect to high school physics. Much of the material available on the Internet contains categorized listings of the types of misconceptions experienced by science students and teachers but relatively few scholarly writings. There are literally hundreds of articles available in academic journals, most of which are readily available.
The dominant topic over the past two decades, within the field of misconceptions in physics has been mechanics (i.e. motions, forces vectors etc.). The largest numbers of studies completed on misconceptions in physics have focused on students' comprehension of forces and kinematics. (Wandersee, Mintes & Novak, 1994). This is not surprising given the amount of time spent on mechanics in introductory physics curricula in high school and first-year university programs. What may be surprising is despite the amount of time spent on mechanics how tightly high school students cling to Aristotelian and impetus based theories of motion (Committee on Undergraduate Science Education, 1996; Wandersee, Mintes & Novak, 1994). Many of these incorrect conceptions about basic ideas of force and motion come from the student's intuitive interaction with their environment but often are not "un-learned" in the physics classroom. The misconceptions of Newton's Third Law (Brown 1989, Brown and Clement, 1987; Maloney, 1990) may be more understandable as comprehending action-reaction pairs requires abstract thought.
The sampling of the literature represented here focuses on the types of misconceptions commonly encountered by the high school science teacher. Many of the sources of misconceptions are also discussed along with some of the methods found to challenge such incorrect beliefs. Finally the novel role that the use of technology has found in overcoming students' misconceptions is examined. Common Types of Misconceptions
There are several types of misconceptions in the learning of science (Tobias, 1987). Distinguishing between types of misconceptions will help the science teacher in identifying their students' difficulties. This is an essential first step in overcoming these problems (Eckstein & Shemesh, 1993).
Preconceived notions or preconceptions of the natural world are popular conceptions rooted in everyday experiences. For example, people observing moving objects slowing (decelerating) mistakenly believe that the force responsible for the motion is getting "used up" (Marioni, 1989). Such misconceptions are very common because they are rooted in the most common activity of young children, unstructured play. When children are exploring their surroundings, they will naturally attempt to explain some of the phenomena they encounter in their own terms and share their explanations (Terry, Jones and Hurford, 1985; Kyle, Family & Shymansky, 1989). When children arrive at an incorrect assumption these preconceptions are also misconceptions!
Factual misconceptions are falsities often learned at an early age and retained unchallenged into adulthood. For example, the idea that "lightning never strikes twice in the same place" is clearly false, but that notion is commonly buried within the teachers' and students' belief systems (Committee on Undergraduate Science Education, 1996; Dykstra, Boyle & Monarch, 1992).
Vernacular misconceptions arise from the use of words that mean one thing in everyday life and another in a scientific context. For example, the term "work" in the physics classroom refers to the result of multiplying a force measured in Newtons by the straight-line distance moved in metres. The introduction of the definition of work in a physics class can present many challenges to the teacher (Clement, 1987). The power (change in energy per unit time) concept is a similar example (Committee on Undergraduate Education, 1996).
Conceptual misunderstandings arise when students are taught scientific information in a manner that does not encourage them to settle any cognitive disequlibrium (Dykstra, Boyle & Monarch, 1992). In order to deal with their confusion, students construct weak understandings. Consequently are very insecure about these constructed concepts. An example of this is the very common "Force as a property of an object" misconception (Brown, 1987). Forces are dependent upon and related to objects but are not properties of them, yet students continually perceive forces are intrinsic to the object (Maloney, 1990; Marioni, 1989.)
Some Sources of Misconceptions
Misconceptions can result from deficiencies of curricula and methodologies that do not provide the students with suitable experiences to assimilate the new concept (Ivowi & Oludotun, 1987). It is rarely that misconceptions result from the lack of reasoning abilities that are necessary to assimilate the new concept (Renner, Abraham, Grzybowski & Marek, 1990). Although vernacular and factual misconceptions can often be easily corrected, even by the students themselves, it is not effective for a teacher simply to insist that the learner dismiss preconceived notions and ingrained nonscientific beliefs (Hammer, 1989). Recent research on students' conceptual misunderstandings of natural phenomena indicates that new concepts cannot be learned if alternative models that explain a phenomenon already exist in the learner's mind (Committee on Undergraduate Education, 1996; Tao & Gunstone, 1999).
Early misconceptions can haunt a student's science learning until the misconception is confronted and overcome (Brown and Clement, 1987; Hewson & Hewson, 1983). Students can become confused in physics and mis-learn because of any number of factors. Language usage, everyday experience, analogies, metaphors, examination papers and textbooks (Ivowi and Oludotun, 1987) can cause students difficulty in forming acceptable understanding of physics concepts, theories and laws (Brown and Clement, 1987; Maloney, 1990). Somewhat surprisingly, textbooks have been found to be the most significant source of misconceptions in the physics classroom (Ivowi and Oludotun, 1987). This is unfortunate as an American study shows a huge dependence on the textbook by high school science teachers (Renner, Abraham, Grzybowski & Marek, 1990). Textbooks can mislead students because of poor writing and/or poor editing.
Often these misconceptions are incredibly durable as many studies have shown students to hold beliefs in contradiction of those used to correctly solve problems (Hammer, 1989; Schultz, Murray, Clement and Brown, 1987). The tenaciousness of such misconceptions is not due to the difficulty in acquiring a new concept, but rather the learner's reluctance to relinquish the old familiar misconceptions (Hewson & Hewson, 1991; Terry, Jones and Hurford, 1985). These old concepts are so near and dear to the learner as they developed over time through personal observations of the learner's environment and have grown from firm intuitive beliefs (Kyle, Family & Shymansky, 1989). These intuitions may be not even consciously held but still exert a great influence on the learner (Shultz, Murray, Clement and Brown, 1987). Confidence in the misconception increases over time and becomes more entrenched despite instruction to the contrary. Unfortunately, traditional instruction has little impact on removing deeply rooted misconceptions (Brown and Clement, 1987; Kyle, Family & Shymansky, 1989).
Misconceptions often reflect a basic lack of understanding hidden beneath the ability to use equations to solve problems (Sandanand & Kess, 1990). Many students get through traditional assessments of scientific understanding by merely correctly identifying the known and unknown variables from the problem and then plugging them into the correct formula, which generates the correct answer.
Since concept learning is usually incremental, misconceptions can impede learning greatly. Misunderstandings will lead to conflict later in the student's academic pursuits if not corrected promptly (Feldsine, 1987; Schultz, Murray, Clement and Brown, 1987) as deep conceptual grasps of certain topics are essential for further physics learning. Students and even teachers at the secondary and post secondary levels often have misconceptions in many areas of physics (Dobson, 1985).
Newton's Third Law is often misconceived by students in high school and beyond (Brown,1989). This is partially due to textbook design, as opposed to misconceptions being included in the text or images of the book (Maloney, 1990; Roach, 1992). Traditionally textbooks skim over the third law in terms of examples and resources when compared to the pages allotted to the first two laws. Some texts even confuse the third law with momentum (Brown and Clement, 1987; Roach, 1992). The third law needs to be treated in greater detail as it is key to understanding the qualitative aspects of force within Newtonian mechanics (Brown, 1989). .
Student Centred Approaches to Challenging Misconceptions
Too often teachers of physics consider their students to be "clean mental slates" and act accordingly in order to fill their "empty vessels" (Marioni, 1989; Mestre & Touger, 1989). The problem with this approach of course is that the vessels are not empty but contain preconceptions. Students' naïve theories or preconceptions may lead to misconceptions and thus may interfere with accepted concept development (Mestre & Touger, 1989). Even when the teachers consider the students knowledgeable they may fall into the dominance trap assuming that children's conceptions of the natural world are easily replaced by the lessons of the teacher. Not only inexperienced teachers fall victim to this trap and students' learning often suffers. Recent research has demonstrated how different individual learners can be, therefore teaching methodology should vary accordingly (Linder, 1993; Novak, 1998; Scott Asoko & Driver, 1991; Tao & Gunstone, 1999; Wandersee, Mintes & Novak, 1994)
Students confronting misconceptions through verbalization of understanding is common to many stepwise approaches to teaching and learning strategies for conceptual change (Marioni, 1989; Scott, Asoko & Driver 1991). If students can grasp their difficulties verbally, they are a step closer to overcoming them. This requires teachers to place a greater emphasis on listening in the classroom when having the students verbalize their conceptual understandings (Mestre and Touger, 1989). In a well-managed classroom, peers may constructively criticize each other's statements and thus each other's understanding. Students can refine each others sample answers to problems. This method will also sharpen the student's critical thinking skills (Stein, 1987). One on one teacher student time is useful as well as small group discussions in helping students identify their own misconceptions (Committee on Undergraduate Education, 1996)
Secondly, having students make verbal statements of understanding to clarify and confront misconceptions is very productive. Brown and Clement (1991) emphasize student oral and written explanation of their conceptual understanding as a method of teacher's isolating misconceptions. Peers may criticize each others statements constructively and thus criticize each other's understanding through this process. In doing so, the students can refine each other's sample answers to problems. This process will also sharpen the student's critical thinking skill (Stein, 1987).
While it is not a common practice within physics education, answering essay style questions requires students to review and reorganize their knowledge of the concept at hand in order to explain their understanding of the domain. Setting essay assignments that ask students to explain their reasoning help students identify misconceptions. In short answer or essay type questions, students cannot hide their conceptions behind formulae as they have to demonstrate their understanding in order to answer the question. (Committee on Undergraduate Education 1996; Renner, Abraham, Grzybowski & Marek, 1990).
Other student centred methods for identification of misconceptions have been proposed by Tobias (1987) and others. Most of these techniques require the student to keep journal style records of their learning and problems they encountered in learning (Hammer, 1989; Gordon, 1996). Many of these approaches employ metacognitive principles. Some approaches are more explicit in their use of metacognition as they require the student to consciously think about how they learn best. Metacognitive approaches can definitely help students understand where they are having difficulty with their understanding of physics. Also, further application of metacognition will help students overcome general learning difficulties (Novak, 1998).
The concept map has been a very popular topic in this literature for at least 15 years. Concept maps illustrate the relationships between ideas in a knowledge domain as lines graphically linking keywords, which represent concepts in the domain. (Fraser & Edwards 1987; Moreira, 1987; Novak & Gowin, 1984). Moreira (1987) demonstrates how concept maps, if constructed in the correct method, show not only a student's conceptions within a portion of a given knowledge domain but also propositions within that domain. (N. B. propositions are two or more concept labels linked by words in a semantic unit.) A knowledge domain is an area of related concepts within a field of study (Fraser & Edwards, 1987). For example, if physics is a field of study then dynamics could be a knowledge domain within that field. Concept maps illustrate in a hierarchical manner, the conceptual structure of a given portion of curriculum (Moreira, 1987; Novak & Gowin, 1984).
In a similar fashion the drawing of free body diagrams is useful in helping students overcome misconceptions in mechanics especially when considering Newton's third law (Maloney, 1990). Having the students identify the agent and the object requires that they look for the two bodies that are interacting. This is preferable to the Aristotelian thinking where the force is regarded as a property of the object. Drawing free body diagrams is useful in illustrating how forces interact in complete systems (Roach, 1992).
Socratic teaching (Clement, 1987) maximizes the in-class discussion of the knowledge domain and therefore helps in identification and confrontation of any misconception. Socratic teaching requires the teacher to give a lesson through a series of questions, which will encourage the students to develop their own answers. This method requires a fair amount of skill on the part of the teacher, which can only develop over time with practice and experience. (Seifert, 1997). While not being explicitly reflective practice, the use of concept maps, free body diagrams and Socratic teaching all have elements of the metacognitive approach as they cause the learner to confront their knowledge of the domain in question.
The Role of Technology
Various technologies have been shown useful in confronting and remediating misconceptions. Schuell, (cited in Krajcik, 1987) sets the tone for activity based learning in science; "What the student does is actually more important in determining learning than what the teacher does." (Kyle, Family & Shymansky, 1989) If lab experience is to be used as a tool for conceptual change, the emphasis in the lab must shift from rote procedures to the procedural skills of planning, testing and revision which underlie all problem solving (Stein, 1987). Computer based labs and especially simulations because of their time efficiency, allow students to ask "what-if questions" (Carlsen & Andre, 1992; Coleman, 1997). When students have the freedom to ask such questions and receive near immediate (real time) feedback they are accessing a powerful tool for conceptual change (Hennesy et al, 1995). Computers take the drudgery out of science activities and thus encourage students to take part in science fairs and similar learning experiences (Hasson & Bug, 1995; Kelly & Crawford 1996). The immediate feedback possible with microcomputer based labs allows learners to focus on conceptual goals (Mestre & Touger, 1989; Stein, 1987). Dykstra, Boyle and Monarch (1992) also support microcomputer based labs as a tool for teaching conceptual change. Well designed instructional provisions such as structured handouts are used to guide discovery and to keep students on task thereby ensuring the success of such activities (Stein, 1987).
Computer simulations run within a constructivist classroom will bring the students to question their own conceptions (Dykstra, Boyle and Monarch, 1992). These simulations provide the learner with a range of learning experiences (Tao & Gunstone, 1999). Commercially available computer simulations help students avoid forming misconceptions (Coleman, 1997) and can be used to challenge student conceptions through the presentation of discrepant events (Tao & Gunstone, 1999). Computer-based labs have also demonstrated the ability to promote proper conceptual development through activity-based learning (Dykstra, Boyle & Monarch, 1992). Simulations can help students learn about the natural world by having them see and interact with underlying scientific models that are not readily inferred from first hand observations. (Krajcik & Lunetta, 1987; Dykstra, Boyle & Monarch, 1992). Martinez-Jimenez et al (1997) claimed that the students who used interactive physics simulations received better marks in freshman physics courses. This follows constructivist model closely as students are building their understanding through their interaction with these learning activities. When the learner poses a conjecture to the computer the simulation system provides a response from which the student can draw a conclusion. Over time, this leads to concept development. Stein (1987) made several observations of students developing acceptable conclusions using microcomputer-based labs.
Carlsen and Andre (1992) examined the effectiveness of simulations along with conceptual change texts in overcoming preconceptions about electric circuits. The study examined groups using computer simulation of electric circuit design and testing, groups using only the basic electricity textbook and a group using both text and information providing simulations. They concluded that the use of the simulation did not improve learning over that of using the text. However, when the simulation and text were used in tandem, the students did acquire a more sophisticated model of a series circuit. The conclusion drawn was that simulations do help students overcome their misconceptions.
A classroom intervention using a computer-augmented curriculum for mechanics indicated that computer technology can stimulate conceptual change in students (Hennesy et al.,1995) Hennesy et al. investigated the effectiveness of simulations and practical activities on stimulating conceptual changes in students. The study examined conceptions of force and motion. The results on posttests reveal that the experimental group displayed more sophisticated reasoning and less alternative conceptions within these domains. The conclusion drawn was that computer based simulation of physical phenomena stimulates positive conceptual change.
Analogical reasoning as a tool for helping students overcome misconceptions is described by different researchers as bridging analogies or chains of analogies (Clement, 1987; Schultz, Murray, Clement & Brown, 1987; Stein, 1987). Computer-based tutors have been programmed to use bridging analogies or conceptual chains to tutor students in such topics as forces in static (Schultz, Murray, Clement & Brown, 1987). The software "chooses" how to present information to the user dependent on their responses.
When a student is having difficulty with a problem, software tutors can make use of bridging analogies in the form of text and dynamic visuals that may be presented in a chain. This chain allows the student to transfer from misconception to "correct " (i.e., accepted in the view of physicists) intuitions. A misconception for a given problem may be challenged by a correct concept and these compete in the student's mind until the student comes to understand the correct concept with the software tutor's help. This process only works if the student can forget their incorrect intuitions (Schultz, Murray, Clement & Brown, 1987). Sophisticated integrated software is being developed by researchers that provide students with instructor-customized simulations as well as hypertext tutorials (Martinez-Jimenez et al, 1997). This tool combines the benefits of simulation and tutoring software. The literature clearly shows that the latest generation of computer-based simulations can not only diagnose, but can remediate misconceptions in physics (Tao & Gunstone, 1999).
Discussion: Implications for Teaching and Learning
Strategies for Challenging Misconceptions
It is possible for students to have two distinct perspectives of science (Kyle, Family & Shymansky, 1989; Marioni, 1989). One view of science is reserved for the formal learning setting while the other is used outside that setting in everyday life. This is contrary to the purpose and nature of science. If science is to be an explanation of the natural world then for each phenomenon there is a best possible explanation in the form of hypothesis, theory or law. Good science teaching attempts to imbue learners with the best possible set of explanations of phenomenon or behaviours so that they will be valid and hopefully even intuitive in the lab as well as in the "real world" (Tobias, 1987).
The teacher and student have a role to play in discovering the student's misconceptions, that is, what the student falsely believes to be the accepted scientific model (Clement, 1987; Dykstra, Boyle & Monarch, 1992). It is incumbent upon the teacher to help the student confront the misconception in order to cause a ids-equilibrium so that new scientifically acceptable information can be accommodated into the learner's existing knowledge (Tao & Gunstone, 1999). Following is a sample of strategies found and supported by various authors across the misconception and conceptual change literature. Some of these strategies were explicitly mentioned in the literature review section and are repeated here to discuss their implication in today's science classroom. Teacher's learn very quickly that students individual needs which require the employment of various strategies.
Analogies
Analogical reasoning has been refined for use in the classroom and is encapsulated nicely in the bridging analogies strategies. The teacher's correct use of bridging analogies can help the student span the conceptual gap between anchor (a mastered concept) and target (misconceived) concepts (Clement, 1987). A teacher can help a student move conceptually from anchor to target by using a bridging analogy (Clement, 1987; Schultz, Murray, Clement & Brown, 1987; Stein, 1987). Finding an analogy that has commonalties with the anchor and target concepts builds a bridge between the concepts. Sometimes when the conceptual gap is too large several analogies may be employed in a structured chain between the target and anchor (Stein, 1987). Teachers may use a bridging analogy B and possibly a series of analogies B1, B2 and B3 to get the student to go from an anchor concept to a target. Clement (1989) calls this use of several bridges "stretching the domain."
An example of stretching the domain could be used to move the learner from understanding simple circuits to complex circuits. An anchor concept would be a simple series circuit that is analogous to a bird's eye view or a map of an oval racetrack. The next link in the chain would be a map (another bird's eye view) of a small town village or neighborhood. In both the neighborhood map and the parallel circuit as there are more than one path that could be taken from one point to another. This map would be analogous to a parallel circuit. The last link would be that of a street map for a city. This street map would be analogous to a complex circuit as many paths could be taken. The complex circuit of course is the target concept.
The analogical reasoning strategy can just as easily involve a series of analogous demonstrations presented sequentially for comparison. An example from Newton's third law may be helpful in clarifying this point. A book is lying on a table, gravity pulls the book towards the center of the earth (action force). Many students cannot identify the reaction force given the action force of a book lying on a table. If the instructor has used the analogy of the hand on the spring where the hand is analogous to the book and the spring is analogous to the table the concept may be clarified. The idea being that most students will understand the book on the table (target concept) after the instructor teaches the more comprehensible hand on a spring example (anchor concept). This approach, regardless of the concept to be taught, is heavily laden with the need for concrete examples and demonstrations as they help students develop visual models of the concepts under study (Brown, 1989; Clement, 1987; Stein, 1987).
Concept Mapping and Diagrams
Most, if not all students, will develop a misconception at some point in their academic career. Identification of their students' misconceptions can help teachers minimize their occurrence. Until the late 1980's, identification of a student's misconceptions beyond guesswork and intuition was limited to clinical interviews in the manner after Piaget (Feldsine, 1987; Posner & Gertzog, 1982). These interviews were designed to ask subjects questions about their thought processes according to a comprehension protocol (Rice & Feher, 1987). This process however, was extremely difficult for large groups such as physics classes (Novak & Gowin, 1984). The introduction of concept mapping has greatly improved this process (Moreira, 1987). This is a critical first step in overcoming them in developing a teacher's ability to discover their students' misconceptions. Through concept mapping, students learn to visualize a group of concepts and their interrelationships within a domain (Fraser & Edwards, 1987). In a similar fashion when students are required to label forces and agents when drawing their free body diagrams allows their teachers to easily identify the students' misconceptions (Maloney, 1990).
Lets take a moment to describe how concept maps are constructed. A concept map (see figure 1) is a schematic device for representing a set of concept meanings embedded in a framework of propositions (Moreira, 1987; Novak & Gowin, 1984). These propositions are symbolized as lines graphically linking keywords, usually contained in boxes or ovals which represent concepts in the domain. (Fraser & Edwards 1987; Moreira, 1987). Prepositions or verbs are inscribed along the connecting lines to help clarify the relationships between essential concepts. These maps illustrate to both students and teachers the small number of essential ideas they must focus on for any specific learning task (Novak & Gowin, 1984).
To construct a concept map for a given domain the learner has to examine all the constituent parts of the domain (of which they are aware) and schematically arrange them given the relationships that exist among them (Moreira, 1987; Novak, 1998). The construction of concept maps is not unlike the procedure for creating food webs which students may encounter in intermediate science or high school biology. Students refine their understanding of the domain while constructing their concept maps. They not only becomes familiar with the sub-concepts but also with the interrelationships existing within the domain (Fraser & Edwards, 1987). Concept maps can be used as a formative evaluation tool (Moreira, 1987). Feldsine (1987) shows how the concept map is not only a diagnostics tool but also a learning tool. We have seen in the literature that concept maps can be valuable to the science teacher in many ways, this begs an important question; "how can concept maps be used in the physics classroom?"
(Figure 1: A Sample Concept Map, Committee on Undergraduate Education, 1996)
The use of diagrams has also been shown to be an effective strategy for encouraging positive conceptual change in the physics classroom (Maloney, 1990). Some instructors have found success through assigning their students to sketch diagrams of given phenomenon to demonstrate understanding. Having the students draw a sketch of a phenomenon or concept at hand can be very illuminating to the teacher. There is an example available from the National Academic Press web-site. When asked to draw a sealed flask full of air that had half of the air removed, students drew flasks that contained half air and half empty space (Committee on Undergraduate Education, 1996). Obviously, this drawing assignment was illustrative for teacher and student.
Often in mechanics free body diagrams are essential tools in problem solving. Free body diagrams show all forces acting on an object in a given situation. This exemplifies the challenge to the learner to explicitly identify the agent and object whenever we label a force (Maloney, 1990). Having the students identify the agent and the object requires that they look for two bodies that are interacting, rather than treating the force as a property of the object of interest as a thing in itself. Spending time drawing free body diagrams, using tracing paper to superimpose one on the other is useful in illustrating how forces interact in the complete system (Roach, 1992). Inspection of these during class-work time can often show teachers where students are having difficulties in mechanics. Assigning such illustrations as homework assignments however would not be as accurate an indication of the student's own conceptions but more a reflection of collaborative efforts.
The Committee on Undergraduate Education (1996) says that before embracing the concepts held to be correct, students must confront their own beliefs along with their misconceptions and then attempt to reconstruct the knowledge necessary to understand the scientific model being presented. This process requires the teacher to:
Identify students' misconceptions.
Provide a forum for students to confront their misconceptions.
Help students reconstruct and internalize their knowledge
Reflective Strategies
Strategies for helping students to overcome their misconceptions are based on research about how we learn (Committee on Undergraduate Education 1996). Helping students to reconstruct their conceptual framework is a difficult task, and it necessarily takes time away from other activities in a science course. Many teachers consider this time a very worthwhile investment in the student's learning and the success of the course (Feldsine, 1987).
Teachers must encourage students to test their conceptual frameworks in discussion with other students. Small groups and one on one tutorial sessions are very useful in confronting misconceptions (Committee on Undergraduate Education, 1996; Fraser & Edwards, 1987). Having students make verbal statements of understanding to clarify and confront misconceptions is very productive. Brown and Clement (1991) emphasize student oral and written explanation of their conceptual understanding as a method of teachers isolating misconceptions.
A similar strategy requires the student to answer essay style questions instead of the usual quantitative problem solving questions. Answering essay questions requires physics students to review and reorganize their knowledge of the concept at hand in order to explain their understanding. Setting assignments that ask students to explain their reasoning in an essay style, helps students clearly identify misconceptions (Renner, Abraham, Grzybowski & Marek, 1990).To answer essay type questions, students cannot hide their conceptions behind formulae as they have to demonstrate their understanding verbally (Committee on Undergraduate Education 1996, Renner, Abraham, Grzybowski & Marek, 1990). Teachers can build on this by requiring students to constructively criticize their peers' answers and thus critique each other's understanding. In doing so the students can refine each others sample answers to problems as well as sharpening their critical thinking skills (Stein, 1987). Concrete Activities
Instruction, which facilitates conceptual change, must be very concrete, well planned and demonstrative. Students need to see and do lab activities in order to replace their misconceptions (Kelly & Crawford, 1996). Misconceptions can be confronted fairly well using demonstrations to illustrate conceptual content (Mestre & Touger, 1989). The learner must be actively engaged in confronting their own misconceptions. Brown and Clement (1991) suggest the use of qualitatively oriented and engaging lab exercises along with concrete examples. While quantitative data may be collected in such exercises, the "analysis" questions will require short answer, non-mathematical answers. It is believed that such questions and answers are crucial in causing conceptual change. Demonstrations may be used to spark constructive thinking in class discussions (Clement, 1987). Students need to build up qualitative, intuitive understanding before they master quantitative understanding. They must also must develop an awareness of their own preconceptions and actively criticize them (Clement, 1987; Dykstra, Boyle & Monarch, 1992; Novak, 1998).
If traditional instruction doesn't adequately affect conceptual change then novel approaches are required (Tao & Gunstone, 1999). The use of group collaborative discussion is one intriguing recent innovation in science classrooms that has had some promising results (Gordon, 1996). Computer based simulations are another unique method of clarifying student's conceptions (Martinez-Jimenez et al 1997). Innovation is essential for methodologies to develop. Microcomputer Based Laboratories
Computer technology has been transforming high school physics classrooms before much of any technology was in other classrooms. Technology has been steadily creeping into the physics education environment since the introduction of the slide rule in the seventeenth century. Significant differences were noticed in the 1970's with the invention of the pocket calculator. The decades of the computer revolution have truly allowed students to begin to confirm their conjectures in real time with immediate feedback. The ideas mentioned earlier of the usefulness of the visual tools such as the concept map and free body diagram are technologically manifested in the computers ability to display graphical and other visual interpretations of data. As computer technology has advanced the technology has become more useful in terms of analyzing, collecting, graphing and modeling data. More recently the computer has been used for presenting concepts, simulating phenomena and tutoring; thus assisting students understand abstract ideas in physics (Martinez-Jimenez et al, 1997).
Microcomputer-based laboratories are a well used strategy for laboratory investigations which have been demonstrated as a tool to help students correct their misconceptions in physics (Adams & Shrum, 1990; Kracjik, 1992; Kelly & Crawford, 1990; Martinez-Jimenez et al, 1997). The capability of microcomputer-based laboratories to transform (in real time) data from each experiment into a graph, a most powerful form of information presentation, is something that has not been possible in the past (Adams & Shrum, 1990). Real-time graphing may be one of the key elements in helping students construct science concepts and graphing skills because it provides opportunities for students to connect the production of the graph with the physical manipulation of the materials. Even small delays in graph production of 20-30 minutes, hinders students' concept development (Adams & Shrum, 1990). Real-time graphing also provides opportunity for students to modify the initial or experimental conditions and immediately see the effect of their modification on the resulting graph (Krajcik, 1992).
The combination of the abstract graphing ability of the microcomputer-based laboratory technology with the real world experiment allows for what Adams and Shrum (1990) call the "immediate abstraction." Students can answer "what if" questions, rather than just answer questions supplied with the laboratory manual. The immediate abstraction is the result of the process where the student bridges the gap between concrete and formal operations. The flexibility of the computer integrated environment gives students more of an opportunity to plan and design their own experiments (Krajcik, 1992).
When students are using microcomputer-based laboratories, cycles of data acquisition, analysis discussion and reframing of the research question can be created. The collected data can be viewed in various formats and can be manipulated to answer questions as the students develop them (Kelly and Crawford, 1996). Students using microcomputer-based laboratories "have unprecedented power to explore, measure, and learn from the environment" (Krajcik 1992). This process may foster learning by allowing students to operationalize and test their initial conceptions, generate and reconcile problematic data and test their ideas. . We may have called this "immediate abstraction" an intuitive leap in earlier days. By shortening the time between the experimental procedure and the graphical analysis, we have improved the learning process by shortening the intuitive distance. This should not be viewed as an attempt to rush the student or speed up the scientific method; but it is designed to encourage the making of connections. Much of the rich information obtained as a graph and produced during an activity must surely remain associated with the graph (Adams & Shrum, 1990).
Computer representations (graphs, charts etc.) are meaningless without meditation and analysis; they must be brought into the discussion through the "interpretive lens" of the student (Kelly and Crawford, 1996). Graphical images of abstract relationships support reflective thinking when they enable users to compose new knowledge by adding new representations, modifying old ones and comparing the two (Gordon 1996). Students still need to talk curves and squiggles into concepts and ideas (Kelly and Crawford, 1996). Microcomputer based lab activities presenting graphs to students in real time result in educationally significant achievement on graph-interpretation tasks (Adams and Shrum, 1990).
An important outcome of using microcomputer-based laboratories is that more time is allowed for critical thinking, problem solving, and self-monitoring skills (Krajcik, 1992). There is a lot of complexity in a science lab exercise and microcomputer-based laboratories apparently don't simplify anything as the pace at which cognitive processes occur has increased due to the speed of the computer. Teachers employing microcomputer-based laboratories therefore need to be aware of this significant difference and adapt their methodologies accordingly.
Research into metacognition suggests that learners need to become aware of the processes of their learning as distinct from the content of learning to improve their learning outcomes (Gordon, 1996). That is, in a pre-lab discussion for example, students may need to be reminded that they are to draw conclusions from the data, extrapolate from the graph etc. Teachers can utilize meta-cognition and constructivism as a background when employing microcomputer-based laboratory activities very much parallels the scientific method. As students seek to confirm or deny the hypothesis using the analysis of their results they are constructing knowledge that is new to them. This process is very much dependent on the "immediate abstraction." Microcomputers used as laboratory tools may offer a fundamentally new way of aiding students' construction of science concepts (Krajcik 1992).
Simulations
A common complaint in content laden science courses is the difficulty of cover all the prescribed content including time consuming lab activities. Computer simulations, because of their time efficiency make this a real possibility (Tao & Gunstone, 1999). Purchasing prepackaged simulations available commercially for every topic would be cost prohibitive. The use of commercially available simulation producing environments allows teachers to create their own computer simulations to suit their individual needs.
Science laboratory activities "consume" large amounts of specimens, chemicals, glassware and related materials. Computer simulated labs provide long term savings after substantial initial investments. Experimentation can therefore be limited in traditional settings due to time and money concerns but much less limited when simulations are employed (Coleman, 1997).
A computer simulation of a phenomenon runs in minutes, instead of the several hours or days sometimes required by traditional physical methods. Along with giving students greater efficiency, it enables them to investigate more variables (Coleman, 1997). Computer simulations can provide teachers with a time-efficient, cost-effective instructional strategy that can provide students with the opportunity to clarify their misconceptions.
Summary
There are many types of misconceptions that trouble high school physics students. There are several sources of misconceptions as well as many effective means of discovering them. In general, teachers should learn to discover student's misconceptions and learn methods to confront them. The research literature suggests many effective strategies to remediate misconceptions. Many of these are student centred approaches that have visual contexts such as concept mapping and diagrams. Others are focus on more language-based approaches both verbal and oral. High and low technology based strategies for challenging misconceptions provide the teacher with many methods to help their students.
The microcomputer has impacted the physics lab greatly and is a tremendous tool for remediating misconceptions. New technologies such as the graphing calculator could soon be the standard in high school physics labs. The internet is rapidly becoming a resource for single topic simulations that run over the internet using Javascipts or Java Applets for example. The effectiveness of these newer technologies will be researched in the very near future.
The literature currently available more than adequately answers the research question. Fortunately, it is a positive answer; yes, there are many ways through which a teacher can confront a student's misconception. Eventually these methods lead to positive conceptual change. As with all things educational however, there are no guarantees. It is acknowledged that the teaching and learning process is a complex endeavour. This is no doubt contributed to by the complexity of the typical high school student and the milieu in which they interact. There is a plethora of research available concerning misconceptions in general as well as literature regarding specific topics within physics curriculum. Teachers are then faced with the task of discovering students misconceptions on an individual basis and implementing effective strategies to help any student in need.
While the learner is at the centre of all strategies, it must be remembered that teachers have to master not only the content of physics but a variety of diverse strategies that promote positive conceptual change. A blending of reflective, concrete graphic and technological strategies are required of the physics teacher in order to be effective in promoting positive conceptual change. Knowledge of cognition, conceptual change theory, constructivism and meta-cognition underlie most, if not all of the strategies suggested in this paper. While physics is rigorous course for high school students, the teaching of the subject is becoming an increasingly complex undertaking.
