Making Chemistry Learning More Meaningful Jazlin V. Ebenezer Department of Curriculum and Instruction, Math and Science Instruction, Faculty of Education, The University of Manitoba, Winnipeg, MB, Canada R3T 2N2 Current research on human learning and current knowledge about the processes that humans use to construct new knowledge both show oromise of a ~ ~ l i c a t i to o nlearningchemistryT~hispaper discusses ~ u k b e l ' slearning theON (1) . . in coniunction with the work of Novak and Gowin. namely, concept mapping and V diagraming (2). Both of these instructional strategies are based on a constructivist perspective. They are considered to be successful contributions for effective and meaningful instruction: learning the material, evaluating student progress, and teaching laboratory techniques and concepts (3-14). Ausubel's Meaningful Learning Theory Ausubel's theory emphasizes the nature of meaningful learning as contrasted with rote learning (15).Ausubel gives the following definitions. Meaningful learning is the nonarbitrary, substantive,nonverbatim incorporation of new knowledge into cognitive
structure.
Substantive Learning
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Substantive karnine occurs when learners make a eonmous effart to identify the key ronrcpts in the nrw knowledge, such as solurc and mlvent, and relate them t o a n d experiences with salt drinks.
For examole. soR drinks contain carbon dioxide eas (solute) disso1;edin the water (solvent). The student-should also relate these concepts to other characteristics of the soR drink-the sweetness of the dissolved sugar, the sourness of the dissolved acids, and the characteristic tastes of the various dissolved flavors in the soR drink. Obviously then, soft drinks contain a mixture of substances, even though they appear as a single homogenous substance. Thus. nonarbitrani learning and substantive learning both require a conscibus efforton the part of the learner. Nonverbatirn Learning
Rote learning is the arbitrary, verbatim, nonsuhstantive in-
Nonverbatirn learning is the product of nonarbitrary and
To illustrate the application of this concept, let us apply it to solution chemistry. Figure 1is a concept map that represents the kev conce~tsand ~ ns in a unit - r o.~ o s i t i o covered on solution chkmist&
Verbatim learning occurs when d e f ~ t i o n sare memorized without stopping to consider the individual or combined meaning of each word in the definition. The students are engaged in verbatim learning when the teacher writes or dictates the following definition of the term "solution" and the students merely memorize this defmition without considering the meanings of the emphasized concepts.
corporation of new knowledge into cognitive structure.
NonarbitraryLearning Ausubel also gives the following definition. Nonarbitrary learning is learning in which the learner
must choose to fit or relate new knowledge into the existing cognitive structure.
If a student is learning what a solution is, hopefully the student will relate this knowledge to what is already known, such as associating the term "solution" with a soft drink.
substantive learning.
A solution is a mixture of two or more substances that appear to have only one set of physical properties.
At the end of the unit on solutions, most students will correctly supply such a defintion, and the teacher might happily assume that the students have mastered the concept. However, within two or three days, the students are likely to have forgotten these definitions that were memorized by rote (16). Rote Learning Rote learning is the opposite of meaningful learning. Ausubel stresses that the distinction between rote learning and meaningful learning is not a dichotomy, but a continuum. While teachers expect students to explain a given concept with appropriate scientific and technical terms, some students choose their own terminologies to communicate their understanding. For example, in 1976, one of my students in the final year of a high school chemistry class gave the following definition of solute and solvent. Solute is the stuffthat dissolves in another stuff. Solvent is the stuffthat dissolves the stufE
Figure 1. A concept map representing the key mncepts and propositions taken from a unit on solution chemistly. 464
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Here, the student has chosen different word sequences that are meaninfil to him to define solute and solvent. I t can be said that the student is on the continuum from rote learning to meaningful learning. As his ideas progress and as he learns the language of chemistry, the student will progressively advance to giving a definition that is substantively similar to those widely accepted.
are reconciling in their minds that there are liquids hesides water that can dissolve substances. Furthermore, they may wonder why certain liquids dissolve only certain substances. Thus, students integrate the newly learned concepts into what thev have alreadv " acauired and conclude that there are othe; liquids that are solvents. At first, it may seem that there is no relationshin between these lianids. But when integrative reconciliaGon takes place, &dents understand readily the grouping of these liquids as solvents. Sometimes, creative students may probe even further and construct novel integrative reconciliations. For example, a student might he curious to find out why a certain liauid dissolves in one solvent and not in another. To understand this, the student would begin by categorizing solvents and solutes as polar or nonpolar, eventually making the generalization that polar solutes are soluble in other polar solvents. Thus, the student would conclude that "Like dissolves like." In probing the nature of solvents, the student has passed through a process that Novak calls high-order integrative reconciliation. Novak equates creativity with the ability to form high-order integrative reconciliations. Novak asserts that rote learning tends to inhibit the search for such an intemative reconciliation (1 . 7).. Figure 2 shows a concept map to illustrate how progressive diffkrentiation and integrative reconciliation might take place in the cognitive structure of a student. The example concerns a student's further inquiry into the general concept "solvent". A
F gure 2 A concept map to I lustrate how progresswe dlflerennanon ano ntegrat ve reconct iatlon m ghl take place In the cognll ue structure of a student when hehhe engages in further inquiry of the general concept "solvent"
The teacher is expected to cover much information. In trying to keep up with the teacher's pace and in preparing to take tests and examinations, students often resort to memorization and rote learning. Hence, rote learning is apt to become a common phenomenon in chemistry classes. Subsumption Ausuhel also gives the following definition. Su6sumption is the idiosyncratic nature of meaningful learning in which new knowledge is usually incorporated
Le., subsumed or anchored)into more general concepts. Most students, for example, have the notion that a solution is always made by dissolving a solid in a liquid. This distorts the new knowledge that air is a solution. However, when students consider that air is a solution, they have subsumed this knowledge into a more general concept of solution. Progressive Differentiation Progressive differentiation is the progression of concepts in the student'smental structure.The concepts become reorganized, elaborated, more ~recise,and both more indu-
sive and more exclusive
For example, the students have the understanding that anything that seems homogenous is called a solution. Thus, students might categorize homogenized milk as a solution when it is more accuratelv described as a susnension (emulsion). When students eome to recognize the'difference between a solution and a susuension-and that milk is a suspension-they are in the process of differentiation. Integrative Reconciliation Integratiue reconciliation of eonceph has occurred when two or more concepts are seen to relate to each other in a new manner to describe a new perceived regularity.
For example, when students observe that cleaning fluid dissolves a stain and that turpentine dissolves paint, they
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Strategies for Meaningful Learning of Chemistry Novak and Gowin claim that concept mapping andV diagraming will helo students to construct new and more piwerfuimeanin& of concepts and principles in the area of study (18).In the subseauent sections. illustrations are given show how concept mapping and v diagraming can be used in a chemistry class.
ConceptMapping Concept mapping can be used in a number of ways while developing an instructional unit. Getting the Big Picture The conceot mao can be used bv the teacher as an advanced orgakzer tb present the &dents with ahig picture of a unit. Students are then less likely to view knowledge as bits and pieces of information. They will see each topic or lesson as inteerated rather than isolated. After intmducing an instru&onal unit in this manner, the teacher can draw back from the larger picture and focus the students' attention on the details of a smaller segment of the unit. Examining tthe ConceptionsAlready Held Concept maps can be constructed to examine students' starting points before an instructional unit begins. The maps will do more than identify the range of concepts and ideas that the students hold before instruction; they will also reveal the students' alternate conceptions. The t v become aware of teacher thus has an o ~ ~ o r t u n i to students' conceptions ofihe topicinder study. Also, the students can be made aware of their own understandine ..of the topic with their own concept maps. It then becomes easier to olan activities either to modit% students' thinking or elaboiate upon their ideas. In ad&tion, by wnstructing the concept map, the students are helped to recognize that they already know something about the new lesson or types of study. This can increase their motivation, attitude, and interest. Volume 69 Number 6 June 1992
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Comparing the Maps Students' Understanding Students' Doing During the course of the unit, the students FOCUS QUESTION can be given an opportunity to review their concept maps. The students will no doubt evaluate Kinetic Molecular Theory practical applicationtheir map in light of what they have been learnfood and medicine description of a liquid is ing. With the teacher's help or even in wnverused to explain solid-liquid sation with their peers, the students will be soiutions. Knowledge Claims able to spot their alternate relationships Solution is a mixture. among concepts. In addition, more concepts Prlnclples Solution is homogenous. and appropriate scientific terms might be eviSolute dissolves in a solvent. A homogeneous mixThe substances are in different dent in the second map. A better relationship lure of two or more between the teacher and the student can be desubstances. Its composition may veloped when they share the progression of Transformation ideas in chemistry in discourse and wnversafizz carbon hear tion through the exposition of maps (19). Concepts dioxide At the end of the unit, the students can refine color orange see or correct their second set of concept maps. To solute, solvent, gas, liquid evaluate the student's work, the teacher might solid, solution, effervescence. sweet sugar taste even have the students present a portion of pressure, homogenous, mixture, substances, dissolve, physical their concept maps to the rest of the class or Records have the students explain their maps individu- change, chemical fizzing sound ally to the teacher. bubbly I would recommend that the students map orange in wlor their concepts without much reference to their tastes sweet text books. It would then clearly reveal the has orange flavor students' thinking, and the teacher would be clear able to remedy the situation if alternate assumptions are made. In this manner, concept EVENT mapping can he effectively used as a learning DRINKING ORANGE CRUSH stratem that enables students to actively cre- L ate cozent knowledge of chemistry. Figure 3. A Vdiagram showing grade 11 chemistry students' understanding of a"solution"e.g., (OrangeCrush).
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1
V Diagraming
The "Knowledge V" is a simple heuristic device developed by Gowin in 1977. It is used to illustrate key ideas regarding the nature of knowledge and the process by which new knowledge is constructed in laboratory teaching. Figure 3 represents a V diagram for a simple activity. I constructed it with the help of the grade 11 chemistry students. It was done as a review lesson on the third day of instruction on a unit on solution chemistry. I began the first day of constructivist teaching of the chemistry of solutions in line with the Driver's instructional model (20)of "orientation and elicitation". Orange Crush soda was served to the students to orient and elicit their prior knowledge of solution chemistry. ~h'students hadsome notions of kinetic molecular theory of matter before my introductory lessons on solutions. During the first two days, I dealt with the nature of solutions by providing the students with many everyday examples, such as sugar dissolving in water, air, and tooth flling. Distinctions were made between a true solution and a colloidal suspension with the help of a demonstration, "The Tyndall Effed-from sulfur to sunsets". Classmom Work with the VDiagram On the third day of instruction, in the form of a review. and to introduce a strategy for laboratory learning, a V di: agram was introduced and constructed. Students needed some help completing the "Theory" section of the diagram; I had to remind them of some material from their previous lessons. Otherwise, students actively constructed-the sections of the V diagram themselves through teacher-directed questions. An example is T h a t questions can be asked from our experience with drinking Orange Crush?" We started at the point of the V, which denotes the object or the "Event" that will be observed. The object in our activity was the Orange Crush soda, and the event was tasting it. The "Focus Question" was V h a t is a solution?" 466
Journal of Chemical Education
The students' experiences with drinking Orange Crush in chemistry class were entered in the "Records" section. For example, the effervescentoverflowing of the dissolved carbon dioxide bubbles from the ovened can caused one student to jump up from his seat. The students heard the fizz. They also tasted the sweetness of the dissolved sugar and the sourness of the dissolved acids. They recognized the characteristic flavor of the Orange Crush. We made a chart of their observations from the "Records" section under the heading "Transformation". The next question was "From your data, what concepts can you think of in terms of what we have already learned about solutions?" These were recorded under the headmg "Concept". Then under "Knowledge Claims" we listed what we had learned from the activity. Finally we began to examine the principles and theories that were euidine our work. (During the ~reviousweek. the teache; exa&ed the students9-undeistanding of ki: netic molecular theorv of liouids in a unit test. Thus. it was easy to translate the studknts' understanding of kinetic theorv to solutions.~We also recorded some vractical a.~.o l i catiois under "Value Claims". In summary, the students learned a new way of representing knowledge. They learned how to construct knowledge from the observation of events and obiects. An attempt was made to answer two questions o&n posed in chemistry t e a c h i ~ How? : (under "Principles") and Why? (under "Theory"). In asking these crucial questions and attempting to answer them, the students pmbed conceptual systems that scientists have constructed about the nature of solutions. (These are represented on the left side of the V diagram.) Then these principles and theories were related to the right side of the V diagram, which consists of the methodological elements of knowledge-making.
The teacher should stress active interplay between what the students observe or do in science and the evolving concepts, principles, and theories that guide scientific inquiry The Knowledge V is a simple, yet powerful, heuristic that can acmmplish this purpose. Visually, the V highlights the interplay between the two sides of the paper that the student will label "My Understanding" and "My Doing", thus directing attention t o the '%vent" and explaining it. As seen in the diagram, this is the point at which theory and practice coteminate.'
Conclusions Pedagogy, which is built on adequate theoretical perspectives such as Ausubel's learning theory, can provide a sound foundation for chemistw instruction. In s ~ i t of e the stated concerns, both concept"mapsand V dia&ams may helo teachers elicit and restructure students' ~ r i o knowlr edge. Thcsc tools can also help teachers plan a large mental mao for how the unit should be covered i n order to link stude1;ts' ideas with school chemistry
Some Concerns about Concept Mapping and V Diagraming . While ~rofoundclaims are made for the efficacv of mncept mapping and V diagraming, researchers and teachers using al have stated the follow- these ~ . e d a-~-o g i cstrategies ing concerns.
Acknowledgment The author wishes to thank Dr. Gaalen Erickson and Dr. Stuart Donn, The University of British Columbia, Vancouver, BC, Canada, for reading an earlier version of this paper.
'There are problems in teaching students how to use the techniques. There are difficulties in convincing students to accept the strategies. .There are difficulties in getting students engaged in the strategies. Complex concept maps are confusing due t o many Lines and
connections. .Constructing and evaluating concept mapping is a fairly time-consuming process for teachers who have limited teaching time and a vast syllabus to cover. Evaluating a concept map and assigning a grade in the manner prescribed by Novak and Gowin seem unjustified. 'Students are often confused by the conceptual side of the V diagram and often become frustrated. They often do not readilv discern the differences amone the terms used. Technque may heeome an end in i t d f , with the science becoming decondary to it. Thrs is a big mirmkr. W h e n "simple" maps are presented hy "cxperrs" they ran rrinforce misconcepts, thus creating pedagogical damage.
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h he last seven paragraphs in this section were paraphrased from the article "V diagramming for laboratory teachingllearning" in Catalyst, the Journal of the British Columbia Science Teachers' Association of the British Columbia Teachers' Federation.
Literature Cited 1. Amsubel, D. P: Novak, J. D.; Hanesisn, H. Edvcotionol Pwhology: A Cognitive V e w , 2nd ed.: Holt, Rinehart and W~nsten:New York,1918. 2. NO"&, J. D.; Gowin,D. B, Learning now to h m ; Cambridge university: Camhfidm. 1 9R4. -~~~ 3. Ault, C. R.:N O V B J. ~ , D.; Gdwh, D. B. Sci.Educ 1W,68,441 4. Bmmbv. M. Rm.Sci Educ IW. 13.9. 5. ~ b e n e r &J. Y Cofolyst I M ,33(3),30. 6. Edwards. J ; Rasel KRas. Sei. Edue 1W,13,19. 7. Fen8ham.P J.:Garrard,J.;West,L.Res Sci.Edue 1881,11,121. 8. Lehman, J.D.; Carter,C.;Kahle,J, B, J. Re. Sei. Teach. 1986.22.663. 9. Novak, J. D.Amr B i d lboeh. 1979,41.467. 10. Novak, J. D.Amr Bid. Teach. 1881,43,12. 11. Novak J.D. J C&m.Educ. 1984.61.6W. 12. Novak, J. D.; Gowin.D. 6.: Johansen. G T.Sci.Educ 1988,67,625. 13. Sieben, G. In Pmedings of the LndlnhrnatiourlSeminar on Mlsronmptiomand Edirwtioml Sfmtogiii in 802- and Mofhemaflrs;Now&, J., Ed.; Cornell Univerai*: Ithaca, NY,1981. 14. Parsons-Chatman,S.; Siehen, G. Paper presented at the m u d meeting ofthe Ca. nadian ~ssociationfor currievlum Studies Canadian Smietv for studies ul m u eation: Winsdor, Ontario. 1988. 15. Novak, J. D. hEdvcotional Psychhlogy Ssrieri: Ccgnifiii Sfrfrfum and Ccccphral Chonge:We% L H. T:Rnes A. L., Eds.:Aeademic: Florida, 1985:p 190. 16. Novak, J. D.: Gowin. D. 6. Learning How to h o r n ; Cambridge University: Cambridge 1984. 17. Novak, J. D. In Edumtionol psyeh0lagySeries:Cognifiw Sfruclum and Cono~plvd Change; West, L H. T.: Pines A. L., E&.;Academic:Florida, 1985;p 194. 18. Nausk, J. D.; Gowin.0. B. L w r n o l g How lo L a m : Cambridge University Press:
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"O. .=A"-"..."..-a-,.""-.
.om
19. Roth, WSei. Teach. 139057.31. 20. Driver, R. Paper prepared for the International Seminar,Adolescent Development and Schoal Science; Kin@ College, London, 1987.
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