Chemical Education Today
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Talking about Science by Kenneth S. Lyle and William R. Robinson “When I use a word,” Humpty Dumpty said in rather a scornful tone, “it means just what I choose it to mean—neither more nor less.” “The question is,” said Alice, “whether you can make words mean different things.” Lewis Carroll, Through the Looking-Glass and What Alice Found There
Language is the means by which we give meaning to our experiences: Try thinking for a moment without using any words. We, as individuals, are constantly interacting with our environment and attempting to make sense of our experiences of it. Take a moment and look around the room. What do you see?—a chair, a computer, a clock, a photograph, a door, a tape dispenser, etc. What you observe is described in words that have meaning for you based on your past experiences. If you see something unfamiliar or outside of your conceptual understanding you still attempt to make sense of it in terms of that understanding—for example, “a long thin, silvery, needlelike, metallic object.” The meanings for the words we have are a result of social discourse (interaction with others through spoken or written words or images). Through such discourse we share understandings of common experiences that assist us to construct and/or modify our own understanding of the experiences that words describe, or to confirm our understanding of those words. Much of learning science involves learning to use the specialized language of science in reading and writing, problem solving, and directing laboratory activities. “Talking science” is not simply talking about science, it is doing science through the medium of language. According to Lemke (1) “Talking science” means observing, describing, comparing, classifying, analyzing, discussing, hypothesizing, theorizing, questioning, challenging, arguing, designing experiments, following procedures, judging, evaluating, deciding, concluding, generalizing, reporting, writing, lecturing, and teaching in and through the language of science.
The discourse in a science classroom is generally intended to facilitate learning science, to assist individuals in the understanding the scientists’ view of the world, and to develop the ability to “think scientifically”. The choice of words related to thinking processes used in classroom discourse should help students develop the cognitive skills understood and practiced by scientists (e.g. observing, describing, etc.). However, as Janice M. Wilson notes in her paper “Using Words about Thinking: Content Analyses of Chemistry Teachers’ Classroom Talk” (2), instructors may be using words in their discourse that could be hindering rather than helping their students meet this objective. Opportunities for discourse in the science classroom are valuable in helping students develop the conceptual 18
understanding and skills related to science as scientists know them. Students benefit from opportunities to express their understanding and to listen to the understanding of others, including the “accepted” understanding as seen by the group we call scientists. From this classroom discussion the students can confirm or modify their current understanding and construct new knowledge of the discourse patterns of science. Unfortunately, a great deal of class talk may not be helpful in developing students’ abilities to talk science. “Look at the reaction of sodium in water,” is a common type of instruction in the classroom. What is it that the instructor wants the students to do when they “look at” the reaction? Observe? Predict what will happen? Compare the reaction to that of some other metal or liquid? Use the reaction as a model of behavior? Form hypotheses about the identity of the products produced? Explain what is happening at the molecular level? While students can probably infer the instructor’s meaning from the context of the statement, they receive no guidance in the use of more appropriate scientific language. This could interfere with development of more specific communication skills. The use of simple words or colloquial expressions can even hinder student’s comprehension if the context is not clear. Confused students often practice face-saving inaction. Rather than expressing their ideas, many confused students remain silent so they do not appear “wrong” in front of their peers or their instructor. If social discourse is valuable for developing conceptual understanding, student silence could retard this development. Teachers’ Language in Classroom Discourse Talking science requires the use of words with slightly different meanings. Words with slightly different meanings that can be categorized under a more general word are called metarepresentative words. Metarepresentative verbs such as predict, observe, hypothesize, solve, compare, and design fall under the general category “to think”, and are called metacognitive verbs. These verbs all describe cognitive processes but each is slightly different from the others. Verbs such as explain, describe, and criticize fall under the general category “to say”, and are called metalinguistic verbs. Both the metacognitive and metalinguistic verbs are involved in, and important for, conceptual development. It is through the understanding of the meanings and the use of these verbs that individuals are able to think about their experiences and express their thoughts to others. It is the use of these metarepresentative words by teachers in classroom discourse that was investigated by Wilson (2). Wilson audiotaped and analyzed the teacher discourse for the frequency, the nature (simple, colloquial, or more specific) and the context of the metacognitive and metalinguistic verbs used by five teachers in six secondary classrooms during 69 lessons covering chemical equilibrium. In total, the
Journal of Chemical Education • Vol. 79 No. 1 January 2002 • JChemEd.chem.wisc.edu
Chemical Education Today
five teachers used 117 different metacognitive and metalinguistic verbs in the 69 lessons. (See ref. 2 for a complete list and frequencies of the verbs used.) The average number of metarepresentative verbs per 10,000 words of teacher talk was 112. With the average number of total words per lesson being 2345, only verbs that were mentioned on the average of 4 per 10,000 could be expected to appear once in each lesson. Of the 117 verbs used, only nine averaged 4 or higher (in descending order of frequency)—look at (10), see (9), write (7), work out or through (7), tell (7), know (6), think (6), explain (4), and say (4). Verbs used in talking science, e.g. predict, hypothesize, observe, and conclude, were used less than once per lesson. Not only were simple, more ambiguous terms used more frequently than more precise scientific terms, but also they were used to represent a variety of different meanings. For example, Wilson observed the following uses of see: See what happens in the reaction, meaning observe. See what you can do with problem six, meaning solve. See if the temperature has an effect on the reaction rate, meaning measure. See if there is any difference, meaning compare.
There were few differences in the frequency or the usage of metarepresentative verbs among the five teachers studied. Two teachers placed more responsibility on the students to perform the designated thinking task with the remaining three tending to use their own thinking processes as a model for the students. One of the teachers was studied in a similar situation six years later. The number of metarepresentative verbs used increased (38 to 46) with the relative frequency of usage almost doubling (59 to 114 per 10,000). However, the usage of the more explicit scientific terms remained infrequent. The teacher explained that he believed that usage of the simpler terms facilitated the understanding of the conceptual content. Significance of the Results Although one cannot generalize the results of Wilson’s study to the classroom discourse practices of all teachers, it suggests that we might wish to consider the choice of words that we use in our classrooms. Experience tells us and research has shown (3) that colloquial language is more engaging to our students than formal speech, and we often use less formal language to keep our students’ attention. However, we also owe our students an opportunity to hear and use words that are more appropriate for scientific discourse. Our choice of words can have strong effects on outcomes and expectations. For example, one of us (WRR) was particularly struck by the use of the word protocol rather than experiment to describe traditional cookbook introductory chemistry laboratories (4 ). “Teenagers expect labs to work (because they are not experiments, they are protocols)”. When the protocol fails to produce acceptable results, the students lose faith and interest, rather than being stimulated to discover a solution to the problem.
Considering traditional laboratory work as protocols casts it in an entirely different light from considering it as experiments. Kennedy’s study of English language teachers’ explanatory discourse (5) provides a second example of the effect of words. She determined that the most critical factor in the success of teachers’ explanations lay in the nature of the ‘keys’ the teacher used to prompt the students and the variety of keys used. Brown and Armstrong (6 ) have classified those keys in ascending order of cognitive demand: Examples are stating, defining, comparing, interpreting, identifying causes, inferring, and evaluating. (Note the similarity to the terms we use in science.) Kennedy states: Thus merely stating something to the learners makes little cognitive demand on them, whereas getting them to compare or to think of reasons and motives forces learners to engage in more cognitive processing. The latter has advantages for the learners in that the more processing they engage in, the more likely they are to retain the learned item, linking it to other language concepts already possessed.
In summary, it does appear that the choice of words used can have an influence on students’ learning, their development of thinking skills, and the expression of their thoughts. Consequently, we should try to enhance our own students vocabularies by mixing more precise terminology along with our colloquial expressions. For example, “Measure the reaction rate and see if the temperature has an effect on the rate.” If you are interested in your own classroom discourse, you can easily explore it by audiotaping your classroom lessons and listening to your choice of words. It will be obvious from the tapes if you are giving your students the tools needed to develop their scientific communication skills. Literature Cited 1. Lemke, J. L. Talking Science: Learning, Language, and Values; Ablex Publishing: Norwood, NJ, 1990; p. ix. 2. Wilson, J. M. Int. J. Sci. Educ. 1999, 21, 1067–1084. 3. Lemke, J. L. Classroom Communication of Science; Final Report to the National Science Foundation, ERIC Document Number ED 222 346, 1983. 4. Besant, Marty. AP-Chemistry discussion list, October, 12, 2001. 5. Kennedy, J. Language Awareness 1996, 5, 26–39. 6. Brown, G. A.; Armstrong, S. Explaining and Explanations. In Classroom Teaching Skills; Wragg, E. C., Ed.; Routledge: London, 1984.
Ken Lyle, a graduate student in the Chemistry Education Program, and William R. Robinson, his research supervisor, are in the Department of Chemistry, Purdue University, West Lafayette, IN 47907;
[email protected]. Editor’s Note: For another perspective on students’ ability to use chemical language and symbolic representations appropriately, see the article by Wiediger and Hutchinson that begins on p 120.
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