edlled by ELLEN and JAY BARDOLE
Flexible General Chemistry Laboratory Programs
One wav to use this desien in a laboratow ..moaram - has been de-
serihPd h;~. C.Pantaleo iil. Here each student makes one (of alist -~~~ . ~
E. K. M e l l o n Florida S t a t e University Tallahassee, 32306 A t t h e Florida S t a t e University the first lahoratory course, normally t a k e n i n t h e winter quarter, parallels t h e second lecture q u a r t e r in t h e general chemistry course for science majors. Recugnizinga certain h e t r n q y w i t y among s t u d e n t s entering this tirst I a h o r ~ t ~ w(.oarst., y the chelnistry department several "ears a r o asked t h e author with t h e aid of a committee representing all segments of t h e faculty t o revise t h e first lahoratorv course. I n desienine " a flexible lahoratorv . .Droaram t h e a u t h o r m a d e a limited search i n t h e chemical literature for nawers descrihine s u c h flexible wroarams. T h e results of . t h a t search a r e presented i n t h i s paper. T h e bibliography contains references from t h e entire r u n of three journals: J Chem. Educ., J. Coll. Sci. Teaching, a n d E d u c a t i o n i n Chemistrv. T h e articles referred to describe flexible laboratory programs in t h e general chemistry course for science majors. T h e bibliography contains few o r n o references t o qualitative analysis, quantitative analysis, upperlevel courses, a n d high-school courses. F e w lahoratory m a n u a l s a r e included because i t is difficult to find a m a n u a l once i t goes o u t of print. T h e hihliography is cross referenced w i t h respect t o seven criteria. T h e s e criteria a r e examined below with examples where appropriate.
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Criterion A. Here students generally design open-ended experiments after having proved themselves competent on basic exercises. For example, in J. A. Young's "Practice in Thinking" lahoratory course (39) a student is assiened an observable ohenomenon. e.e.. the
students, and the instructor as resources. He then performs the test. He is graded on the quality of his hypothesis, not whether he completely accounts for the phenomenon. Of a total of some 300 phenomena, each student is assigned several (of increasing complexity) during the course of a term. Young's program and other carefully designed programs of this type provide training in a vital scientific skill that is not even touched on in traditional "cookbook" or "verification" laboratory programs. Since each student works on his own project, dry lahbing is impossible. Better students are said to he highly motivated. Several possible disadvantages come to mind. The subject matter must be very carefully chosen so as not to discourage the average student. The very lack of structure in such a program can he quite unnerving to the marginal student. Reagent and equipment cost constitute another area of concern. In large-university laboratury operations the management of such a program through inexperienced teaching assistants is almost unthinkable, although E. F. Bertant (42) has proposed a plan to this end. Criterion B. Students select among or are assigned to different instructor-prepared experiments. The major difference between Criterion A and B is that in Criterion A the student designs the experiment.
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cdfurt)) \\'c~rnrrcumpltr,purifier the p n d u ~t.nnd thm dtmqu;di. tatrve and quantitat~vrnn;tl>sc, dcieloped t h r w ~ hlilw~g.u w k . Each of the complexes poses problems at a similar difficulty and complexity Level. Another implementation which might be termed vertical as upposed to Pantaleo's horizontal design is used in the first laboratory quarter at FSU (12). Here all students first perform a very simple, detailed, low-level experiment designed to test whether the student has mastered the lahoratory techniques and underlying concepts. Far example, in a unit of mass stoichiometry, accurate and precise use of the analytical balance is the skill, and an understanding of the mole concept is the underlying theme. Heavy use of behavioral objectives was made during the design of the experiments. Remediation pathwavs are oruvided for those students who need them.'l'hose students uhu rapidly demonstrate pruiicirmy nrr ullwed tu prurrcd r u higher-lwei expmnwnti rhich hdp them earn higher p r d c w 'l'hrse higher-lrkrl rxp~rimr.ntrdeal with III(III(I wrnplcx + i t ~ m -but 11w concepts are similar to those used in the simpler experiments. Students choose to do the higher-level experiments based on the grade they have decided to eo after. Allied with each block of experiments is an "enjoyment experiment" which all students are free to do. Growing handsome crystals is the "enjoyment" experiment associated with the mass stoichiometry content area. The advantages and disadvantages of this criterion are substantially the same as for Criterion A, although the risks in content choice and management are somewhat lower. Criterion C. The use of remedial loops was touched on just above. Extensive remediation in a program ensures at the very least that all students who pass out af the program were at one time proficient in the skills covered. Criterion D. Students are placed at a Level hased on demonstration of comoetencv at the beeinnine" of the . oroeram. I t would he very interertinn to see a oroeram of this sort inooeration eivenour erowine ~-~ "~ nwareneisof the hetrrwmetry ~n interests, ~umprrenrlrs,mthuirsrm, levelofthestudent populatwm. Refand intrllecrualderelupmr~~tal erences (10) and (53) only touch on this criterion. ~
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Criterion E. Students are free to work in a self-paced manner at times other than the regularly scheduled lahoratory times-pen labs. Perhaps the best known example of completely open l a b (lectures too) is the audio-tutorial botany program of Postlewaite at Purdue. Students come in at any time and do laboratory work at stations where the content is changed weekly. The immediately obvious disadvantage of unlimited open lahs in chemistry is the question of laboratory safety. Many lahoratory reagents are inherently dangerous to use and we are finding that the professor in charge can he held liable in law suits resulting from laboratory accidents. The recent trend inchemistry has been to introducelimitedfleaibility in scheduling short of the completely open lab. For example, in the first lahoratorv course a t FSU (12). students are encauraeed to plan a
