Chemistry in context. How is chemistry portrayed in the introductory

science, and technology that chemical educators convey to university science majors. ... Using a Thematic Laboratory-Centered Curriculum To Teach ...
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Chemistry in Context How is Chemistry Portrayed in the Introductory Curriculum? Peter G. Mahaffy The King's College, 10766-97 Street, Edmonton, Alberta, Canada T5H 2M1 Questions about chemistry's public image have resurfackd recently, prompted in pa$ by media coverage of the negative face of chemistry ( I ) . Symposia a t several meetings of North American chemical professional associations have addressed concerns that the general public is developing "chemoparanoia" a s a result of such media attention. This paper evaluates the overall representation of chemistry, science, and technology that chemical educators convey to university science majors. The specific goal of this study was to assess whether several representative gene r d iintroductoryl chemistry textlr~oksfor science majors signifirantly present the diverse social, cultural, erunomic, rncthodoloeical. --- ~ - , and historical contexts for chemistry. Where textbooks do present the larger context, the balance given to the positive and negative faces of chemistry is examined (2). Discussions about the design of the general chemistry curriculum usually focus primarily on the important "what," "how much," and "when" questions relating to content and balance within the curriculum. While mastering the b a s ~ cprinciplesolchemistry, however, the introductory student of chemistrv also forms images of the scientific enterprise and the d&ipline of chemistry through the exnlicit and imolicit messages conveyed by the curriculum. t h e most significant Apart from the profess&, comnonent of the curriculum experienced by first-year che&istry students is the comprehensive textbook, which defines the basic structure and content of most courses. Science students and scientifically trained citizens are increasingly being called upon by our teehnolofiical sociery to he conscious uf the social, cconomic, and environmental consequences of scientific derisions. The overall image of science held by students is important in shaping the rriticnl consclousnrss wlth which they approach the scwntilic problems they will encounter. Thus, it seems essential that the rhcnucnl educators desimine c u r r i c ~ l ~for m the 21st .-------century be aware of and critically examine the overall representation of science found in present teaching materials. ~

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Methodology The choice of methodolow and some of the outcomes of this qualitative study are inwitably colored by certnin preroncrptions and ;iasumptions. 1 begin with the premise that students should not be indoctrinated with the notion .--------of'ehrm~st a s neutral fact finder. but that it is desiruhlc for a chemical educator to place chemists, chemical theories, data, and reactions in their broader contexts. Such a n approach offers several pedagogical advantages. ~~

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It may present a more "authentic"portrayal of science. ldrntlfy wlth thr

.It may permu the itud~ntto glimpse and human sldr of trxthook suienrirti.

Baseo n part, on a presentation to a symposium en1 t eo 'Genera Cnem stry toward tne Year 2000' a1 tne Tenth lnlernar ona Conference on Chemical Edmatlon. Waterloo Ontarto. Canaoa. A L ~ J S I 1989.

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Journal of Chemical Education

It may equip students to participate more thoughtfully as citizens in decision making regarding societal issues related to science and tachnology Aikenhead (3)has tried to clarify what it means to make a "thoughtful" decision on a societal issue related to science and technology by identifying some sources of conflict brought about by the interaction of scientific and social values. He then explored how teaching collective decisionmaking skills might impact on secondary level science education. A great deal of discussion that has engendered several curricular initiatives has taken place recently about how best to represent science in its societal context to students taking elementary and secondary science courses. These Science-Technology-Society (STS) initiatives ( 4 ) take various approaches to investigating the representations of science in existing curricular materials. Souque describes a methodology developed to identify and clarify a representation of science found in primary and secondary texts referred to a s textbook science (5).A study conducted by Souque for the Science Council of Canada examined the messages about STS interaction in 32 widely used Canadian primary and secondary science textbooks. That study finds that textbook science simplistically misrepresents science and calls for further research on the validity of the representation of science in textbooks in light of recent advances in the history and epistemology of science. Factor and Kooser have produced a critical bibliography of university level chemistry textbwks for nonscience majors in which they attempt to identify the value presuppositions that explicitly or tacitly underlie the content of the texts (6). They placed these texts into three basic categories with respect to their pedagogical design: "drills and skills" (the data of chemistry presented in isolation); "science and society" (emphasis on societal issues arising from the application of chemistry); and "applied relevance" (the provision of chemical facts useful to a student's chosen vocation, usually in the health area). They find that the predominant value transmitted by these nonscience majors texts can be described a s the "scientific (or technological) fix," a belief that any problem or social issue can be satisfactorily resolved by science given sufficient time and research. While it is beyond the scope of this paper to review the approaches to curriculum theory that have shaped the present study and STS initiatives in general, two terms used to describe the curriculum experienced by students should be explained. Eisner (7) and Flinders and coworkers (8) use the concept of null curriculum (what schools do not teach) as a useful device in educational criticism for examining the educational significance of perspectives that are absent in school programs to ensure that they are absent out of choice rather than habit or ignorance. Second, the concept of the hidden or implicit curriculum has been used to describe those pervasive aspects of the culture of schooling that students experience, even though they are not advertised or articulated. The hidden cumcu-

lum is usuallv related to such phenomena a s political socialization, the inculcation of values and social umtrol (9.. Gordon sueeests that the hidden curriculum. which ccachers unintentionally teach and students are unaware they learn. often olavs a . ~ r o f o u n drole in molding- students' image of science (10). Stated in these terms. the present study asks whether the broader context for chemi&y is part ofthe null curriculum for introductorv chemistry students i n majors courses. I t also identifies and ev&ates those messages about science that textbooks wnvey to students explicitly or implicitly. These objectives are achieved by firstexamining the way textbooks use photographs and illustrations and then assessing qualitatively the coverage given to the following topics:

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ductory science wurse would be both interesting and difficult. More than ever, the medium plays a profound role in transmitting the message. Photographs and illustrations may be quite important in forming a first-year student's overall impressions of the discipline. Yet the messages thev collectivelv convev to students about the nature of science are seldom acknowledged and scrutinized by either chemical educators or students. Ironically, photographs and illustrations, which are one of the most visible components of a textbook..mav. function as part of the hidden curriculum described earlier. Photographs and illustrations found in introductory chemistry textbooks fall into the following categories: Illustrations of chemical substances. reactions. techniaues or pwws ol'equipmmt. A text mlxht, fur rxamplr, haw a phcaopph of;iulfur.~evrralphotngrnphi of thr thermal drcumyosition of ammmnm dlrhrunmtr, 2 n d n sehematlc

The history of chemistry 'The scientific method The personal dimension of science The role chemical processes and technologies play in society.

drawing and photograph of a mass spectrometer. Graohs and drawings illustratine . .articular mathematical rrln~ionshapso r chemical theories I