Hugh M. Cartwright University of Victoria Victoria. BC V8W 2Y2 Canada
I
lntegrated Experiments-The
Synthesis Or Time-Consuming Failures?
The process of change in the syllabus of a laboratory course is generally that of gradual evolution. The slow removal of outdated techniques and syntheses, and their replacement by more modern methods, ensures continuity in an established program without endangering its success. Even when some substantial innovation is introduced, the prospect that the innovation might he inappropriate or even detrimental to the program can usually. he guarded against. . Frequently the proposed change is innovative only w i t h the context of the department or university proposing it. By studying the experiences of other universities who have tried similar changes, much can be done to ensure success. Such major changes in structure, syllabus or philosophy of a laboratory course are, a t some stage, felt necessary by most chemistry departments. This paper owes its birth to consideration by the Chemistry Department a t the University of Victoria of the possibility of increasing substantially the proportion of integrated experiments in upper level (3rdl4th year) lahoratory courses. This type of experiment (which combines techniques from two or more quite distinct areas of chemistry) could hardly be called innovative. But an alteration of the mix of experiments in these courses from mainly traditional to mainly integrated would represent a major change in course philosophy, would require a considerable investment in time for experiment development, and could possibly lead to unforeseen problems in the lahoratory courses. In this situation, in which the decision to introduce suhstantial numbers of integrated experiments into the syllabus might seriously affect the success of the program, i t seemed prudent to investigate the experience of other universities with integrated experiments. Accordingly, a short questionnaire was prepared and sent in June 1979 to more than 50 major North American universities. This paper presents some of the more significant findings of the questionnaire. I t will not, I hope, spoil the reader's anticipation of what is to come to note immediately that there is an astonishing degree of disagreement about the value of such experiments. Nevertheless, while there is no concensus, many of the comments made provide a significant insight into why an integrated program may he a success a t one university, yet fail completely a t a second. Where these comments are given below they are reported without being identified with a particular university, since some comments represent an individual's opinion, rather than the official position of a department. lntegrated Experiments There is some disaereement as to what constitutes an integrated experiment,-mainly through confusion with integrated laboratories. I n the integrated laboratory several chemistry courses are run simultaneously in the same lahoratory area. This practice is widespread because of its efficient use of space and personnel. Naturally, the operation of an integrated laboratory has no direct effect upon the course . svllahuses ~~~~An integrated experiment, on the other hand, brings together material from several different areas of chemistry and combines them to produce an experiment which could be used to illustrate the experimental chemistry of any (tf those areas. T h e following are rypicid integrated experiments: ~A
Ideal
Color Centers Alkali halide crystals are prepared and doped with excess alkali to produce color centers (inorganic);the spectra and bleaching characteristics of the color centers are studied (physical)and the properties of such centers described using simple theoretical models (theoretical). Light Scattering by Macromolecules in Solution Macromolecules are oreoared . . at low concentration in solution (polymer,organic);scattering of laser light as a function of cancentration and angle is used to determine the average molecular weight (physical,theoretical). Photochemistry of Diones A suitable dime is prepared using standard synthetic methods (organic);after characterization using IR and NMR, its photochemical degradation is studied (physical) and an attempt made to identify the degradation products (analytical). These experiments proceed in a fashion analogous to much scientific research. This, indeed, is one of the main points made by proponents of 'such experiments. ~ r a d i t i o n kexperiments are regarded as being too narrow to give the student a clear idea of the relationships between different branches of chemistry- relationships he must come to appreciate if he intends eventually to pursue a career in chemistry. This point of viewsand others, will be considered in the next section. Survey Resulls Use of lntegrated Experiments
Of the 34 departments responding to the survey seven include integrated experiments in a t least one upper level s (3rd/4th year) course. The remainina 27 d e ~ a r t m e n t either no longer use, or never have used integrated experiments. Only a single user had no reservations about the experiments. everth he less, as might be expected, users weregenerally enthusiastic in their comments: "Most faculty here are convinced of the value of this course.. . ." ". . . (the facultv)stronelv -.SuDDorts .. our .oroeram.. . ." ". . . istudents)kostly are very enthusiastic and think it is agreat learning experience." "Students are generally quite enthusiastic about content and organization of (the) course." On the other hand, comments from departments which had once used integrated experiments, but had dropped them, revealed considerable dissatisfaction. "They were much more trouble to run and students didn't learn that much better from them" was a typical comment, while one resnondent described his deoartiint's exnerience with integration as "disastrous." Those departments which had not yet tried integrated experiments were generally favorably disposed toward them. It was interesting, however, that while some non-user departments were quite enthusiastic about integrated experiments not one indicated any intention to introduce or consider introducing such experiments into the syllabus. Generally this reticence was due not to concerns of an academic nature, but to more mundane problems which will he dealt with in a section below. The Advantages of lntegrated Experiments
Few r e s p m d ~ n t sfelt integrated experiments had nothing to recommend them. Even departments not currently usmg Volume 57, Number 4. April 1980 1 309
them sometimes put forward persuasive arguments in their favor. Of the many advantages cited, the following were the most frequently mentioned: Integrated experiments show students chemistrv is not seemented
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provide a better overview of chemistry save space, time andlor money.
An interesting difference of opinion between users and non-users became apparent here.-~othusers and non-users agree that there are possible academic advantages to these experiments. significant numbers of non-users Beem to feel in addition that integrated experiments might provide logistical or financial advantages as well; e.g. by the more efficient use of laboratory space. Such advantages seem, in fact, to he mainlv illusorv. - oartlv . . because an intearated course rarelv totally r r p l n c o tr;~ditionalcourses, hut i i often run in nddrtiou to them. The users, with a clearer understanding or what is involved in the actual running of integrated experiments, aenerallv feel that the academic advantages are the prime, and only significant, justification. The Disadvantages of Integrated Experiments As might he expected, users pointed out a number of (for them) minor problems. Only two of these problems seem common to the majority of users. One is the student whose background may be insufficiently broad for the experiment. A common wav of handling such students is described, bluntly, below: "The handout is detailed enough so that any idiot can do the physical manipulations. The theory comes in only when the report is written uo. We do the write-uo in two drafts. The student who turns in a poor lfirst draft is forced to see his TA to get corrections made." Other departments allow students to choose (or choose for to the stuthem) exneriments which are most appropriate -- . dents' hackgrounds. The other difficulty mentioned by several users was that ofiinding suitable experiments. Thii pruhlem is more severe than for tradii~onalcxperimm~s,since rhrre are few textl~ooks in this field. Many disadvantages to integrated experiments were discerned by non-users. These disadvantages were presumably of little consequence to actual users, since the latter rarely mentioned them. Several non-users raised philosophical or academic objections to the use of integrated experiments. The following quotes are representative of those views: "Our experience with transferstudents and graduate students who have gone through integrated laboratory sequences has not been very promising. There are frequentlygaps in their laboratory experience (either rvnthetic or instrumental Gchniaues. , - ~ . . or both). or due to a lack ,~ of redundancy,they seem not to have mastered the laboratory experience as well as those who have taken a more traditional route." " 'Arhitrary' divisions such as (Organic, Inorganic, Physical) are made in euery field to help organize and simplify the material. To promote 'integrated' experiments and sacrifice this organization simply to show the already obvious ties between the areas is educational idiocy of the worst kind." ". . . We have considered using integrated experiments, but the disadvantages seem to exceed theadvantages.. . .In practice it seems that actual laboratory experience is often reduced asaresult of integration and important areas of knowledge are omitted because they cannot be conveniently integrated." ~
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Stlvh comments indicate the cmsidernble degree of doubt some resumdent cliarls felt nhout the academic, rather than logisticai, value of integrated experiments. Why not Introduce lntegrated E x p e r i m p ?
As we have just seen, some non-users object to integrated experiments on academic grounds. But a majority of non-users 310 1 Journal of Chemical Education
appears to approve of a t least limited use of integrated experiments. So why do non-users remain non-users?
". .. it seemed to me that there was agreement in principle that (integrated experiments should be introduced).The matter however was never pursued to the point of design or implementation of experiments. I suspect that inertia played a significant role in this." ". . . We have considered it and there is considerable interest.. . but we have not implemented the program primarily because it would require a major effortof time." "Inertia." "(Faculty are) committed in principle, couldn't care less in practice." ".. .Most (faculty) would be indifferent so long as they were not involved." "There is same moderately serious consideration of this, limited mainly by the extensive faculty effortthat appears to he required." (It would appear that there is a notential market here for an up-to-datemanual of integrated experiments.) Predictably, departments as a whole, and faculty members individually, are generally reluctant to commit themselves to a laboratory program which they see as being likely torequire an extensive investment in time. Similarlv. ".it is understandable that some of the most successful integrated programs are run by departments which have full-time permanent professional instructors to both develop and run the laboratory programs. The Lecture-Laboratory Tie In defense of traditional laboratory experiments it has been pointed out that integrated experiments, because of their academic breadth, correlate poorly with lecture material. Respondents were therefore asked to what extent lecture and laboratorv courses were correlated with each other in their departme&. Onlv seven replies (21% of the total) indicatedthere was some such correiation; and of these, two replies pointed out that the correlation was rather loose. The opinion was expressed that possibly such correlation serves n o purpose: "I am not convinced that the two need to he coordinated. I view the role of the lectureas to teach the facts of science, and the roleof the lab as to teach how to do science." But if we are to accept this viewpoint we are agreeing implicitly that experimental work requires no knowledge of ihror; for succe&ul completion.Thi~nmcept may he a k t true ai lower Ip\,els. I~utfor nhre advanced courses the nllility to make decisions is essential. Are these spectra consiste& with the anticipated product? Are these readings identical within experimental error? What type of impurity could give such a signal? The answers to such questions may well determine the next step in the experiment. T o answer such questions .iuccessfully clearly rrqulrcs mgwe knowlvdge on the Dart ot the student t h m how to verform a distillarion. or measure a boiling point. Why, then, are lectures and laboratories not correlated? Few respondents commented on this, hut our own experience would seem to be typical. Although correlation is academically desirable it is logistically tricky. Upper level courses frequently involve sophisticated equipment, such as spectrometers or snecialized distillation anoaratus. Unless a course enrollment i i extremely small, equidkent limitations prevent all students from completing the same experiment simultaneously, so that experiments must necessarily be tackled in a different order by different students. Faced with a choice of including only less demanding experiments, or giving up lecture-laboratory correlation we, like most other departments, have chosen the latter. Other Results Among other results of the survey, two are of particular interest. As mentioned above, those departments running integrated experiments sometimes encounter problems in finding suitable experiments. All respondents were asked what sources
thev used for new exneriments. The most oooula . . source was ideas from faculty, especially in departments in which faculty members themselves were in direct control of the lahoratorv course. Commercial laboratow manuals were the next mast ~ o p u l a r source, followed closeliby experiments generated by demonstrators and TAs (particularlv in departments in which faculty were not in direct contrb~of thk laboratories). The JOURNAL OF CHEMICAL EDUCATION was the only other source mentioned more than once. I t is interesting to note that only one reply suggested current literature as a possible source-an indication, perhaps, of the difficulty of using an experiment straight from the literature. A final sienificant-ooint was made in a small number of replies which, in one way or another, commented on the imoortance of the resentat at ion" of an ex~erimentto a student. i s distinct from its content:
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"I feel that the choice of experiment is much less crucial to . . . success than how it is written up:. .and how the course is organized and "~ eraded as n whole." "I t h i n k that mrmtwrr 01thr department appreciated thnt them is vmr~dernlhprdng
