Slide-Audiotape Pre-lab Programs for Organic Chemistry J o h n Almy California State College, Stanislaus, Turlock, CA 95380 Numerous reoortsl on the oreoaration.. use.. and effectiveness of slide-au&otape, videitape and film presentations for students oreaarine . . " for laboratorv activities have called attention to the advantages of c o u ~ i s t e n t ,well-organizedla ~~.~ recorded oresentations which the student can olav . . back if n e r e ~ s i l r y . lHecause ~-~ students \,iew pre-reconid presentations before the lab ueriodi herin. more time can be devuted to actual laboratory work. The s ~ c ~ eofs audiovisual s materials in terms of student and instructor acceptance as well as measured student performance improvement has been reoorted for laboratoryzd as well as lecture3 instruction. This report outlines the content and use of slide-audiotape programs which have been prepared a t California State College, Stanislaus. Additional advantages for the use of simple programmed pre-lab instruction and data which indicate its success as a teaching aid are also described.
appropriate laboratory. Those who do not quickly find themselves a t a disadvantage in the lab and on quizzes which are given. The topical outline of each program is presented below:
The Program T h e organic chemistry laboratory program a t California State Colleee. Stanislaus normallv teaches 50 students oer semester. while instruction in -fundamental laboratbry techniques and operations is the first objective, emphasis is placed on each student's experience in personally choosing and controlline chemical c h a n e e ~Preoaratious .~ and assienments which i o not involve tGe teaching of new techniq"es and have a limited accomplishment value are kept to a minimum, and 30%of the laboratory assignments are devoted to the determination of unknowns. Pre-lab lectures have been prepared on slide-audiotape programs. These lectures had previously been given in person nroerammed lecture a t the beeinnine " " of each lab: thus. each . was prepared from carefully reviewed notes of previous lectures and included resoonses to auestions which bad been asked frequently by &dents in tGe past. As in the lectures, the . oroerams exnlain the exoeriments to the extent that the instructor feels appropriate, point out what to look for, demonstrate various manipulations and techniques, and explain what steps are necessary to make proper conclusions. The programs organize the activities and give references to the specific procedures in the laboratory manual5 or instructorprepared handouts. They also introduce the student to the reference material which is available in the college library, such as sample spectra, derivative information, etc. The programs provide instructions and information of immediate value to the student. The four basic programs each span a t least two lab periods and cover only those experiments which require elaboration of published instructions. Scripts prepared in a colloquial style were recited onto tape by the instructor a t a deliberate pace. Sentences appearing on the slides were often repeated in the recording. T h e slides are color photographs of diagrams, checklists, equipment setups, and properly filled out forms, etc. T h e programs were prepared in duplicate. One copy is available in a small room near the lab. The other coov . . is on the central library's reserve shelf. Singer Caramatem equipmcnr" wiih slide-cuing cavabilin has hrtm r~rovidedfm this ourpose. All students are toid to use these programs in advance okthe
Program 3 (15 mi", 11slides, covers three lab periods). A. Qualitative Organic Analysis (aldehyde,ketone, or amine): Preliminary tests, functional group tests; derivatives; identification of the compound using the literature.
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Program 1 (13 min, 13 slides, covers two lab periods). A. Introduction to the Lab: The text and handout materials: lihrarv references: safetv orocedures: cheekine in and out eouioment: crystallization theory and technique; purification using decoloring carbon; suction and gravity filtration;melting point determinatkm. C. Isolation of Lactose: Filtration with filteraide. Program 2 (9 min, 11 slides, covers two lab periods). A. Free Radical Chlorination: Eouioment setuo (differentfrom . . ~ hm r e in the la11 trrt,; r r m s i r r $11 IKIIIIIIP; ~ l r y m r d ~ ~11n t iVI'C. . Theory and l'rartirr. C. Ikhydratiun o f a n hlruhol.
Program 4 (11 min, 7 slides, covers five lab periods). A. Extraction: Solubility and Separation. B. The Mixture Unknown: Separation, functional gmup tests, IR and NMR spectra. Advantages - of the Program -
In addition to the advantages of pre-lab programs reported elsewhere,',2 there are several benefits to our faculty and students. Because of the small size of this institution, the instructor of the laboratory is also the lecturer in the companion lecture course. T h e change in format provided by these programs appears to he beneficial. While the lab instructors give less group instruction, they can now be more available to students individually. The pre-lab programs now provide the students more flexibility in scheduling their laboratory periods because these
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(a) Meloan, C E., J. CHEM. Eouc., 48, 139 (1971);(b) Oarrow, F., Journaiof College Science Teaching, 2,46 (1972);(c)Lagowski, J. J., J. CHEM. EDUC., 43, 501 (1966);(d) Lindenlaub, J. C., EngineeringEducation, 60, 896 (1970);(e)Spears, J. D., The Physics Teacher, 16,586 (1978);(f)Fine,L. W., Harpp. D. N., Krakower, E., and Snyder,J. P.. J. CHEM. EDUC. 54,72 (1977). (a)Lightfoot,0. R., J. CHEM.EoUC., 55, 786 (1978);(b) Pantaleo, D. C., J. CHEM. EOUC., 52, 112 (1975);(c)RusseII,A. A., and Mitchell, B. L., J. CHEM. EOUC., 56, 753 (1979);(d)Howell, J. E., Woodruff,H. F., and Garroway. H. P., Southern Journal ofEducationa1Research, 9,236 H97V \.-.-,.
Barry, R. D., and Carter, R. H., J. CHEM. EDUC.,49,495 (1972). This objective has been encouraged in the "Report of the ConferEDUC., 52, 27 ence on Laboratory Instruction in Chemistry," J. CHEM. (1975). Mwre, James A,. and Dalrymple. David L.. "Experimental Methods in Organic Chemistry," 2nd Ed., W. 6. Saunders Co., Philadelphia. 1976. "Singer Educational Systems, 3750 Monroe Ave., Rochester, NY 14603. Other manufacturers of slide-audio equipment are listed in the Audiovisual Equipment Directory, 27th Ed., National Audiovisual Association, lnc.. 3150 Spring Street. Fairfax. V A 22031.
programs allow two different classes (e.g., both first and second semester) to be run simultaneouslv in the same laboratory. Slide-audiotape programs are inexpensive, (approximately $150 for film, slide development, slide trays, and audio cassettes) and are easily produced. The programs are changed easily to fit course revisions by exchanging slides and dubbing over audiotape. Although there are a number of successful commercially produced programs which explain (with a great deal of technical polish) many of the techniques and procedures which are used, the locally produced programs appear to have more educational impact. For example, the equipment which is shown in the slides is the very equipment they are about to use. From the viewpoint of the students, these programs are specifically designed for them7 'Although complete slide-audiotapeprograms are unavailable for d'mibmion, a sample sheet showing sfx sl des and accompanying script are available from the author upon request
Success of the Program Previously reported results3 indicated that slide-audiotape programs were helpful in supplementing chemistry lecture material. The results of our survey were measured by the number of correct identifications of organic unknowns before and after the introduction of the programs. In the four semesters previous to the use of the programs, 62 correct identifications were made out of a total of 248 unknowns for a success rate of 25%. During the five semesters after the introduction of the progrnm, 1'43 uf L:l7 unknowns w r r correctly idmtiiied for an improved success rote ut'GOS. This improvement reflects students' greater understanding of the objectives of the laboratory and confidence in their work. Acknowledgment The author wishes to thank the Trustees of the California State University and Colleges for support for this project.
Volume 59 Number 5 May 1982
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