C a r l o s Ferraro Universidad Simdn ~ol/var Caracas. Venezuela
Teaching Quantitative Analysis Courses by an Integrated Audiovisual Method
T h e explosive growth of higher education need3 i n Venezuela has produced a critical supply and demand imbalance. This situation has led u s t o search for a new method of teaching chemistry subject t o t h e following constraints: (I) The method should he suitable for large groups of students. (2) The quality of the education should he at least competitive with that of the conventional courses. (3) T ~method P should attain a better use of the teacher's time by eliminating repetitive lectures. Among different methods experimented with during the last decade, i.e., Keller (1-2). individualized or personalized instruction (3-41, use of computers ( 5 4 ,and audiovisual aids (7-II), only t h e audiovisual media courses have shown t h e potential to solve our prohlem.
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Inlearated Audiovisual Methodoloav. Whv and how? Optimal results can he expected only from educational experiments which integrate t h e media a s part of t h e whole educational process (7-11). This fact agrees with the modern thinkine t h a t a media technoloev "" cannot work alone with the complex educational or learning problem. Learning is a problem of didactical methodology, not media technology, and m u s t he attacked and solved as such. An Integrated Audiovisual Methodology (IAM) includes not only the media-with its advantages, disadvantages, and limitations-hut also a whole set of other elements which contribute t o the learning process, i.e., the ohjectives of teaching, t h e students and their environmental, social and nsvcholoeical characteristics. and the ~ r a c t i c a land admin" istrative norms necessary t o have a fluid organization. ~
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Courses and IAM used T h e courses under this experiment are Analytical Chemistry I and,II, code QIM-331 and QIM-332 a t Universidad Simhn Bolivar. These courses cover gravimetric and volumetric analysis only and they are placed in the 6th and 7th trimest,er of the "Licenciatura en Quimica" (eauivalent t o a B.S. plus thesis t o sum u p 15 trirnestkrs). ~ h e l e v kof l QIM-331 and QIM-3.72 can he considered t o be of t h e U S . Junior and t h e texthooks employed are Quantitative Analysis books by Skoog and West (main), Hamilton and Simpson, Brown and Sallee, and Walton and Kolthoff. Students complete their Analytical Chemistry formation with two subsequent Instrumental Analysis courses. T h e IAM we have applied on these courses consists of t h e following elements: The sudiovisual program (AP) is recorded in 20-25 min videocassettes. The total number of tapes are 23 in QIM-331 and 19 in QIM-332. Two p:ograms/week are now substituting 3 hr of conventional lectures. Each session (1'12 hr each) in the charge of an undergraduate teaching awistant (UTA) dwelops as follows: the program is shown without stops. At. the end, the UTA answers any question about the pmpram itself or related to its content. The program then is shown for a second time, hut now it can he stopped any time to answer questions or to clarify points. Maximum number of students per class isset at 40 and a T.V, monitur is placed for each group of 10 students. Much valuable time W8S employed in conventional lectures writing information on the chalkboard and repeating explanations. The AP has eliminated the first and has left repetitions for the second showing of the tape in each lecture in the new system. (2) A studyguide issupplied as a complement to the AP. The content (1)
Table 1. Audiovisual Courses Ouantitative Analysis I and II Results Compared with Previous Conventional Courses OuantitativeAnalysis I Ouantitative Anal~sisI I Conventional ~udiovisual Conventional ~udiovisual courses Courses Courser Courses 1971-77
1978-79
1971-77
1977-79
54% 29% 17%
69% 25%
61 % 28% 11%
7% 6% 7%
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Failed
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6%
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Table 2. Audiovisual Courses Ouantllafive Analysis I and II Distributlon of Grades Compared with Previous Conventional Courses Maximum grade: 5 Fail: 1 and 2
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Ouantitative Analysis I QuantitativeAnalysis 11 Conventional Audiovisual Conventional Audiovisual Courses Courses Courses Courses %
1971-77 ~
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1978
1971-77 -
1977-78
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students with 5
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students with 4
%
students with 3
%
students with 2
%
students with 1
references, ete. (3) An Instruet,or's manual includes all the information to he known
by Instructor. UTA, and students. Two hourslweek sessions are devoted to solving the problems inrluded in the study guide. ( 5 ) Program reviewing sessions, which can he accomplished withT.V. stations consisting of a T.V. monitor, videotape machine and earphonds). These stations are placed in special rooms where the tapes to he reviewed can he accessed. (fi) Pernnal r o n ~ d t ~ t i o with n the Instructor. (4)
T h e elements 1,2, and 3 integrate the first part of the IAM: Information. T h e elements 4 , 5 , and 6 form the second: Assimilation-Reinforcement. T h e third part of t h e IAM is Evaluation which is accomplished hy exams (knowledge) and surveys (Methodology). Results At present, Quantitative Analysis I1 has been taught five times hy this method and Quantitative Analysis I twice, which reoresents in total 25% of the courses taueht since 1971. T h e c o k e s by IAM were taught for the firsctime i n April 1977 (QIM-332) and Amill978 (QIM-331) and keot . hv" this method u p t o the present No contrd~group has been used heretofore because t h e numher of studentsltrimester has not been enough t o have more than one section each time. T h e results, in terms of passed,' failed, and withdrawn students, as well as distribution by grades are summarized in Tables 1 and 2. Table 1shows in both courses a clear increase in the amount of students approved as compared to failed and Volume 57, Number 3, March 1980 / 185
retired students. Table 2 shows an increase in the numher of students with grades 5,4, and 3 a t the expense of students with 2 and 1. The rule of the UTA's in the teaching of the courses has heen and is very important. They did not participate in the development of the new system; however, the apparent success of the system must be imputed to the system itself, because the good results obtained to the present are not due to any curricular changes in prerequisite courses and the exams are being maintained with the same length and content than in conventional courses.
initial cost of these courses can he relatively high2 but can he amortized. In general terms, we think this experience could be adapted to prepare courses on a larger scale. Literature Cited (1) White,d. M.. Clme,.l. S., McAllirtrr.d. W.. J. CHEM. EDl!C..?1. 772 (19721. 121 Peterion. 1). I.. J. CHEM. RDUC.Sd. lfi2 IIJi7i. I:ll Vandenhmucke.A.C.,.I.CHIIM.El~llC..SZ.S1fiilYiSl. (41 Shakharhiri. R.Z...l.CHEM. F D l l C S2.5xR i l s i i l
Summary and Discussion
Although the numher of courses taught by the new method is still not comparahle with the numher of courses taught by the old one we have enough evidence to conclude that: T h e new method has the potential t o he used for large numbers of students organized in groups of 40 studentslclass. T h e quality of education, measured by number of students passed versus numher of students failed, seems t o he better than old C0"rSPS.
The new method saves teaching time which can be devoted to research or teaching postgraduate courses.
Furthermore, we can also say that the methodology seems to be accepted by the students, as can he concluded from results and written opinion of students through surveys. The
186 1 Journal of Chemical Education
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T h e system of grades is based on numerals 1, 2,3,4,5. The best grade is 5; students pass with 3, 4, or 5 and fail with 1 and 2. The quarter consists of 12 weeks, and students may withdraw inscription up t o the 8th week. There is no final exam. Final grade is hnspd on three partial exams-acc~~mulative-on weeks 4th. 8th. and 12th. TheIAM materials were all ,orodured a t the ITnivorcirld SimAn ~~~. Bolivar hy its faculty. Personnel involved include 1professor-producer whoat the same time is theTV artist (the author) and the Audiovisual Department group formed by 1 TV director-producer. 2 cameramen, 1 audio-technician, 1 video-technician. 1 videotape operator. 1 draftsman. Cost of production of one 20-25 min tape including only staff time and materials can he set approximately a t US $200. ~
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