Chemical Education Research in the Laboratory Environment: How

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Sy mposium: What Is Research in Chemistry Education?

Chemical Education Research in the Laboratory Environment How Can Research Uncover What Students Are Learning? Mary B. Nakhleh Purdue University, West Lafayette, IN 47907 Significance of the Problem Laboratorv work is often considered an essential comDonent of any kcience course, yet little research has investigated how students actuallv learn in a laboratorv environment. Students seem to experience difficulty in integrating their understanding of chemical concepts gained in lecture with the physical phenomena observed in the laboratory. This difficulty could be because a laboratory is a complex, information-rich environment. Perhaps students simply become overwhelmed in their efforts to process the information effectivelv. Friedler and Tamir ( I report that secondary students in Israel seemed to experience four major difficultiesin doing laboratory work: (1) an inadequate understanding of the basic concepts under-

lying the lab: an inability to relate their observationsto their theoretical knowledge; (3) an inability to order their observations so that irrelevant details are filtered out; (4) weak links and even gaps in their knowledge which slaw down students'understanding or even mislead them. (2)

Nakhleh and Krajcik (2)also recently conducted an investigation of laboratory with secondary students in this country. They found that students' decisions on how to focus their observations: i.e., what is relevant and what is irrelevant, are influenced by the type of instrumentation used in the laboratory activity. Finally, Mulder and Verdonk (3) a t the University of Utrecht found that college students tended to routinize procedures and that, if these procedures became fully automated without gaining in corresponding understanding, t h e s t u d e n t s would 'encapsulate' these gaps into their knowledge structure. These three papers found remarkably similar evidence across cultures and across made levels that students exDerience barriers in integrating their classroom knowleige with the observations and inferences drawn from laboratory work. This DaDer discusses a . ~.~ r o ~ r imethodoloeies ate for investigating how learning occurs in the laboratory and presents two technioues. n e V-diaeram. . c o n c e ~ tm a ~ ~ i and ming, which can be effectiGe research tools in probing students' understanding of chemical principles. These techniques also can be effective instructional tools that h e l ~students to intemate their lecture knowledge with their laboratory obse&ations. Illustrative examples are drawn from two studies.

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New Ideas about Learning: Constructivist Theory of Learning The Role of Mental Processes Researchers have bemn to investigate the role of mind. i.e., mental states, in leirning. They &knowledge that stu: dents and teachers are thinking individuals and that

learning in the laboratory or classroom is much more than just the transmission of information from one person to another. More and more researchers and educators are building a picture of learners as people who actively construct their knowledge based on their prior experiences and the information that they receive in instruction ( 4 , 5 ) . Because learners literally turn information into knowledge, Wittrock ( 6 ) urges that learners "construct images and verbal representations" that facilitate this process. Laboratory activities provide students with many opportunities to construct these images and verbal representations from their observations and interpretations, and these opportunities, correctly used, should facilitate learning. The opportunities exist for integration ofknowledge in a meaningful way, but it is true also that the barriers to this integration are formidable. Therefore, laboratory can be conceptualized as an opportunity surrounded by barriers. The Role of Incoming Information This process of turning information into knowledge is by no means easv or ~ainless.In fact. we have learned that people intensely resist new inform'ation if accepting that information would reauire extensive re-arrangement of their laboriously consthcted knowledge. The incoming information we have to work with is ~ e r c e ~ t i of o nevents and objects. Events can be loosely defined as anything that happens. Objects can be defined similarly as anything that has-existence and can be observed. ~ G e we-assimilate n these perceptions of events and objects, we begin to create concepts. Novak and Gowin (7)define a concept as a "regularity in events or objects designated by some label" (p 4). In our laboratories and classrooms, students construct these concepts in a complex environment. This environment is created by the professor, the students, the teaching assistants, the curriculum, and the school's policies and ex~ectations(8).This environment also is affected bv the ieelings, thoughts, and actions of the participants ($1. In this com~lexitvand because knowledge construction is not easy, s t u h e n t s b ~ e nare tempted to engage in rote learning rather than meaningful learning. Our task in general chemistry is to try to find ways to

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(1) increase meaningful learning, (2) actively involve students in the process of knowledge mn-

struction, and

(3) empower students to became responsible for their own

learning. V-diagrams and concept maps to both represent the processes of knowledge construction and the structure of that knowledge. Used in this way, V-diagrams and concept maps can influence the teaching and learning that goes on in general chemistry. Volume 71 Number 3 March 1994

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Research Methodologies

Creating a V-diagram.

New tools from cognitive science that match the constructivist learning theory have been adapted to science education research. These tools have the potential to completely change the way in which we investigate learning in complex, natural environments. Some of these tools, such as clinical interviews. alreadv have entered into the research literature as ways in wiich to probe learners understanding of various science topics. In fact, a substantial body of literature is coming into being concerning learners' understanding (and misunderstanding) of science concepts. However, this knowledge is static knowledge because we only see how the learner has constructed that knowledge and not how the learner can use that knowledge. Other tools, such as V-diagrams and concept maps, have the potential to help us investigate learning in the lahoratory both as a process and as a n end product. The remainder of this paper will discuss how these research tools can be used to investigate learning in the laboratory. In the process, illustrative examples will be presented from two studies from the author's research program.

Figure 1 shows the V-diagram format. The diagram is begun by drawing a large Y Because knowledge construction starts with perceiving and thinking ahout events and objects, these are placed a t the point or focus of the V. The focus question is placed in the middle of the V and linked to both sides of the V with a n arrow. This arrow indicates that, in order to make sense out of a laboratory, learners must move back and forth in their thoughts from one side of the V to another. In that case, what is on the sides? On the l e e side are the theories, principles, and concepts that are necessary to make sense out of the events andlor objects we wish to perceive. On the right side are placed the records to be made, the transformations used on the data, and the knowledge and value claims we made as a result of the experiment. Our world view and the theories, principles, and concepts in which we believe determine what we perceive. What we perceive determines what we choose to record. All of these factors affect the transformations, results, interpretations, and knowledge and value claims that we make. Educators have reason to be concerned about lab because we often impose an additional conceptual burden on students by using complex instrumentation in our experiments. Indeed. ever-increasine instrumentation is a hallmark of our science, and, if professional training is our goal, our freshman labs will use more, not less, instrumentation. Therefore, we must do all we can to help students integrate their thinking and doing in the midst of complexity. V-diagrams are one way of helping students think about their own thinking and of realizing that there is a constant interplay between both sides of the V, between knowing and doing. Figure 2 shows a completed V-diagram of a lab on the kinetics of peroxide decomposition which will be discussed further in the next section.

V-Diagramming Background

V-Diaprams (7)are a method of disolavine and thinkine about tGe processes that go into const&ct&g knowledge. And because the ~ r i m a r vconcern of this . DaDer . is with laboratory experiments, V-diagrams are used here as a way of analyzing and evaluating experiments. V-Diagrams are basically ways of displaying information that allow leamers an opportunity to make connections between the thinking and doing that occurs during a lab. The V-diagram allows the learner to see the lab as part of the network of understanding that he or she is constructing about a particular topic.

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Figure 1. The categories of V-diagramming 202

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8. Slope = n 9. Plot lograte vs. log IKII

Figure 2. V-diagram of a lab on the kinetics of H202decomposition.

V-Diagram Study. Barbara Tessier recently conducted a study with freshm a n to investigate how students might r e a d to general chemistry labs if they were taught to V-diagram (9).Therefore, she taught V-diagramming to three students from second-semester general chemistry for science and engineering maiors. I n interviews she robed t h e students as to how-the ?-diagramming had infiuenced their learning, attitudes, or behaviors during t h e labs. The data in the study consisted of the transcribed verbal commentary in the help sessions and interviews, as well a s the V-diagrams t h a t the students constructed. Verbal commentary collected during well-constructed interviews typically yield a rich d a t a set, and these data illustrated students' thoughts and attitudes toward V-diagramming and toward lab in general. Four major trends emerged from the data about laboratory work in general: (1) Students expressed a desire for quality pre-lab discussions. Example: "I think this gives you more of a clue. . . . much more of a clue than the nathine that we usuallv do. . . . If I had had 10 rnmutes at rhc beginning d r h e pen,&or 21) rnmuws, evcn, just discussmg rhli .+tuff-would jave you 45 minutes that you have to re-do something because you messed it up." (lE, 2nd interview) (2) Students felt they did not connect material in lecture with material in lab. Example: "I mean, therell he times where I will not make the connection about what was going on. There Larel probably labs where I never did make the connection. . . I don't think that's the point. I don't think that's what's trying to be done." (lE,2nd interview) (3) Students felt they did not construct understanding of chemical concepts from labs. Ezample: "Alot of it is just regurgitation. You knaw, collect the data, plug it in, hope you get the right numbers and hand it in and eet - vour . mades. I don't know. mavbe what I've done here today has shos,n. . that lark i f artunl ~~

you get in there." (3E, 3rd help session) (2) Students felt V-diagramming was a viable method for learning from lab. Example: ". . . . this time when I was doing it [the lab] when it was getting really tedious and everything, I was just sitting here saying 'Wow, we're making oxygen gas!' but I could've just been in there going 'I'm holding a tube with water in it, waiting far time to go by." (3E, 1st interview) The findings of the study are summed u p accurately by a student who remarked ". . . . I mean, we'd need this wdiagram1 i f we wanted to learn i t [lab material], b u t we wouldn't have to know i t to do a lab write-up. . . . it would help to understand this stuff i n lecture." (3E, 1st help session, emphasis added.) This study has begun to document how laboratory work is viewed from students' perspectives, to identify the barriers to successful integration of laboratory with lecture, and to suggest instructional strategies to overcome those barriers.

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understanding."^ 11.:. la interview, f 4 , Students felt they dld nut wed to knon any chemistry in

order to complete labs. Example: 7 mean it's like a computer eoulds go through the process, you know. I mean, I don't think you have to have the knowledge before you go into-I think it's neat to have the knowledge before you go in-to actually knaw what vou're doine. ... hut I m m n , it'd hr poss~hlctojust S I L thew and gu through it and then when you writr the lab write-up then you understand rvrrythtng-cause I know that's how I almwr ulwnvs d ~ di t hrfnrr " 3E. 2nd heh session.) Two more major trends were found regarding V-diagrams: (1) Students felt increased eonfi-

Concept Mapping Background From the V-diagraming we have seen t h a t knowledge is composed basically of concepts, which we had defined a s ~ e r c e i v e dreeularities in events or obiects. Therefore. we ihould be abre to find some way to display these ideasin a logical fashion. P a r t of the problem i n thinking about how to organize our concepts i s that researchers have begun to discover that we receive information more or less linearly, either by reading, listening, or observing, and t h a t store our reworked information (knowledge) in a networked organization in our brain. Another difficulty i s t h a t t h e concepts in these networks can also connect, or crosslink, to each other. Concept maps are a way of visualizing this knowledge structure developed by Novak and Gowin (7) over a period of many years. BASES

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denee in the lab after using the V-diagramming method. Example: "I do think it [VI helped though, especially when you're doing the writeup, cause then you'll know where you're headed as far as the foeus question, as far as the knowledge claims and Periodic Table value claims. And, so, and you definitely go through the lab, so you definitely know Figure3. Initial base concept map for#0312, microcomputer group. (A) indicates an acceptable link, and what you're going to do when (U) indicates an unacceptable link. Volume 71

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We need one other piece of information before we start to look a t and create concept maps. We can relate concepts to each other by short meaningful phrases. An example of this is the statement "molecules are made of atoms." The concepts "molecules" and "atoms" are linked to each other by the phrase "are made of'. This short statement is called a proposition. A concept map is simply a visual display of concepts that are arranged in ~ ~ e r a r c h i and e s linked in propositions to form a n interlocking network of stored knowledge. Therefore, when we retrieve and think about any one of the concepts in a network, we have the potential to access all of the concepts stored in that network. Creating a Concept Map

The first step in creating a concept map is to think about what is the central concept of your topic, the concept that is a t the heart of your topic and around which all other concepts are organized. Oiten this is the hardest part of drawing a concept map. Sometimes you have to experiment with different central conce~tsuntil vou have a satisfactory map. Fortunately, this ;sually gets easier with practice. Once you have the central concept, you write the term on a sheet of paper and enclose it in a shape, usually a circle, to emphasize that this is a label standing for a much larger set of meanings. Then beneath the central PH concept you addother circles containing concepts that describe your central concept. These circles are connected with relationship lines, and words describing the relationship are written on the lines. These initial concepts will then lead you to other conncids cepts that are placed under this first row. You proceed building your map from the top down and interconnecting t h e concepts with a s many relational lines as you can until you have described your knowledge of the topic a s completely as you can. Figure 3 is an example of a concept map of a students' understanding of the concept of 'base' before performing a series of acid-base titrations as part of a study on how instrumentation influences understanding in the laboratory Figure 4 is the same student's concept map of 'base' after completing the titrations. These maps will be discussed further in the next section. Concept Map Study

that comprise the primary data in this study. Three concept maps were constructed from the initial interview for each student: an acid concept map, a base concept map, and a pH concept map. Three concept maps also were constructed from the final interview for each student. This separation into three concept maps for each interview was done because the maps grew so large that it was impossible to display the relationships properly. Each major concept (acid, base, p ~ is)placed in a cloudlike shape to denote that this major concept references a complete separate map, concepts that are repeated across maps are in a rectangular shape. Of interest in this paper is how the concept maps showed changes in students' understanding of acid-base chemistry that might have been missed ifthe interviews had just been analyzed by developing coding categories and taking frequency counts. analysis of Figure yields the follow. ing information: (1) The student has an acceptable (A) crosslink to the term acid. This is important because it indicates that the stu-

dents are to some extent integrating their understanding BASES

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\ The author recently investitaste rat8o gated how secondary chemistry students' understanding of acidOfIUl lOIU] base chemistry was influenced by the level of information presented by the technology used in a series of acid-base titrations ii~) ir(ui (2, 10).The study used interviews, concept maps, and thinkaloud probcols to collect and an- Figure 4. Final base concept map for#0312,microcomputergroup. (A) indicates an acceptable link, and alyze t h e verbal commentary (U) indicates an unacceptable link.

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of hases with their understanding of acids. There is no similar link to pH on this map. (2) A key concept for this student's initial understanding of hases is 'hvdroeen'. Hvdmeen . . .. is linked to six other coneepts in the map, and the rectan~w1;irshape ~ndsntrh that the twm i s present 1,) othev uwps a s *ell. r u f m u nately, all of the links to hydrogen in this map were coded as unacceptable (U).This means that the student isincorreetly using a key term in Brdnsted-Lowry acid-base chemistry, and this inadequate understanding could lead to much confusion far the student. This mao alsoindicates a maior source of the confusion. The student has an inromplrtc sclccti~nrule that rdcct* the itud~mt'sh e l d rhat hnses have no hydrogen in t h e m . .I The mnp rndloares a posshlt mlrconcpprwn that hades are large hrrnusr rhcy cnn rxpnnd. ( 4 1 Thc map shows six ncrcprablc links and I5 unncwptiiblc Imks. Thls lndlcatrs a vawt and fracrnented undrrstmding of hases

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Figure 4, which represents the student's final understanding of bases, can be compared with Figure 3, which represents the student's initial understanding: (1) The map shows appropriate crosslinks to both acid and

pH. This indicates that the students seem to have further integrated their understanding of hases into two other major concepts. (2) Hydrogen is no longer incorrectly used as a selection rule far bases. Instead, the student appears to be using a more appropriate rule that Bronsted-Lowry bases contain an OH p u p because three appropriate links are made to that term on the map. This rule is still incomplete, hut progress has been made. (3) The miseonceotion that hases are laree " and exoandahle no longer appears. However, the map contains a new misunderstandingthat hases are not harmful and will not burn. (4) The final base concept map contains 19 acceptable links

which appear to be networked to other concepts in an appropriate manner. However, the map also contains 18 inappropriate links, which indicates that the student's understanding, although greatly improved, is far from complete. These concept maps reveal much information about how the student cbnstkcted h i s h e r understanding of acidbase chemistry. A total of 84 maps were constructed and analyzed i n th& study. These maps enabled the authors to document the changes that occurred in students' understanding after completing a series of titrations using different types of instrumentation. These maps also provided part of the evidence for the finding that the students who titrated with a microcomputer-interfaced pH probe constructed a more appropriate understanding of the topic than students using a pH meter or students using chemical indicator solutions (2,10). Instructional Implications We have seen that V-diagrams and concept maps can be useful research tools for investigating learning i n the laboratory. However, they also can be useful instructional tools for chemical educators.

V-diagrams have a t least two different uses in the laboratory. F i r s t , professors can V-diagram experiments for their courses to see if students have been exposed to all the concepts necessary to understand the expe&nent, to check that procedures are clearly written so that there is a logical progression of thought i n the experiment, and to clarify what questions would be good to ask on the postlab in order to make sure the students have grasped the essential point of the experiment. Every time this author h a s V-diagrammed a n experiment i n a research project, some weak-

ness has been detected in the procedure or questions that could then he corrected. In this way, labs can be refined and 'piloted'hefore giving them to students and then finding out what's wrong the hard way. Second, students can diagram their labs a s either a prelab activity or a postlab report. This could be done easily in cooperative grouvs and mieht lead to livelv and fruitful dis&ssions ofwhat the exp&ment was all about. Avariation on this idea is to have students roueh out the V-diagram a s a prelab activity and then modTfy and complete the V a s a postlab activity. The V-diagrams can be scored if the professor wishes to do so. Novak and Gowin (7)recommend a scoring scheme i n which the five major categories of the V are scored: the focus question; the objects and events observed; the theories, principles, and concepts required for understanding; the records and transformations needed to analyze the data: and the knowledee claims that mav he made frnm the expehment. Each of these categories i s assigned a point value from zero to four based on how well that varticular category is developed and how logically i t is connected to the other parts. These scoring schemes are by no means fixed in concrete--you can weight categories, you can convert to percentage, or use whatever scheme best suits your needs. Concept Maps I n the context of the laboratory, concept maps can be used a s a n organizing tool in the prelab and postlab. Have students draw a "first draft" concept map of the concepts listed on the left side of their V-diagram in order to have them start thinking about the relationships among these concepts that they will need in order to understand the lab. Then have them modify the concept map along with the V-diagram a s part, or all, of their lab report. This will provide them with a n opportunity to reflect on the meaning of the experiment and on how the observations made in the laboratory relate to the concepts they had learned in class. Conceot maos can be scored a s flexiblv as V-diaaams (7,. One point is awarded (br every acccptuhlc relationship, ~ n c l u d ~ examvlt~s. ne Sinw hierarchv ~ n d x a t e the s difierentiation of knowledge in a person"k understanding, five points are awarded for each acceptable level of hierarchv. ~ i m i l a r lcrosslinking ~, between concepts in different are& on the map are a n indication of integrating knowledge, which indicates a substantial growth in understanding. Crosslinks are scored a t 10 points each. The total raw score can then be converted to percentages if you wish. Conclusions Meaningful learning frnm laboratory work is apparently very difficult for our students. A barrier seems to occur when students are supposed to integrate the concepts they have learned in lecture with the phenomena they have ohserved in the laboratory. V-diagrams and concept maps are research tools that have been used to investigate these bamers, and they also can be used a s instructional tools to help students integrate their observations into their conceptual knowledge. Literature Cited 1. Friedler. Y: Tamir. P. In The Studen! Lnhnrolnry and ib Srience Curriculum: Hemrty-Hazel. E., Ed.: Routledge: London, 1990:Chapter 6.2. 2. Nakhleh. M.B.; Krajeik.J. S.J. Res. Sci. B o c h r i i ~1993.30. 114S1168. 3. Mulder.T.:Verdnnk.A.H.J. Clzem. Educ. 1984.61.45L453. 4. Witiroek, M.C. Edar. Rycll. 1914,11.87-96. 5 . Bodner G.M. J. Cheni. Edue 1986.63,R7S878.

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