Introductory laboratory: A new exploration - ACS Publications

we mean a laboratory in which students are motivat- ed to work harder than one of us (FDT) has seen in over. 30 years of undergraduate teaching. By su...
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Introductory Laboratory-A New Exploration Frederick D. Tabbult, Jefhey J. Kelly, Robert S. Cole, Clyde H. Barlow, and Donald V. Middendorf Evergreen State College. Olympia. WA 98505 For many, i t may seen that all that can he said about the introductory chemistry laboratory has been said. We urge those who subscribe t o this n e w to read on, for in this paper we report on the success of a unique lahoratory and the simple, exportable premises that have lead to its success. By success we mean a laboratory in which students are motivated to work harder than one of us (FDT) has seen in over 30 years of undergraduate teaching. By success we mean a laboratory in which students gain the confidence and ability to solve nroblems more difficult than vou would exDect them to do by a process that invokes responses ranging from frustration to euphoria. By success we mean a laboratory that students cite as the most important learning experience in the whole course. By success we mean a course whose eurollment has increased by 50% over the past three years for which we believe the lab is largely responsible. Since our introductory course is somewhat different, we shall first explain how our course operates to provide a context in which to understand the laboratory. The introduction to university or honors-level physical science a t Everereen is a vear-lone. .. . combined -. team-taueht. calculus, chemistry, and physics class. The coverage in these threesuhiects is orchestrated todovetail with each other and with the iahoratory, which we call Explorations. The course is called Matter and Motion after Clerk Maxwell's hook of the same name. This is a full-time course. That is, students take nothing else, and faculty teach nothing else. Consequently the faculty have comGlete control over the scheduling of students' class time. The course consists of daily lectu~es/workshopsand weekly Explorations and seminar. I t is taught for three 11-week quarters. Sixty students typically take the class. and three facultv tvoicallv teach it. We find t h a t this intebated approach G;Gdes the student with an excellent understanding of interrelations among calculus and the physical sciences and of the continuum from theory t o application. Students tend to view phenomena and objects not as systems belonging to individual subject areas. With careful attention t o fine-tuning to maximize coordination and integration, the whole can be more than the sum of its parts. Finally, Matter and Motion, like most Evergreen co&ses, has a book seminar where issues of science and society are discussed. First. to he honest. the oremises that we cite here were not formaliy derived and then the laboratory design based upon them. But asMatter and Motion hasevolvedover the paat 15 years to its present form, we recognize what is different that has led t o the current success of the laboratory component. They are basic ideas so simple and obvious we want to share them. ~

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1. Introduetow students. whether thev be maiors or nonmaiors, honors students or not, private or publiccollegestudents,have

a greater rapacity for solving real problems in the lahorntory than we typically giw them credit. 2. Any laborau,ry exercise that you have studenta do must be sufficientlyinteresting that you would want ta do it yourself, had you the time. Furthermore, it is important that ntudents be aware of that. 3. Having an idea or theory occur more than once during the year, although cloaked in a different mantle, gives a perspective of it

940

Journal of Chemical Education

so that a student is better prepared to use the theory as a tool. In fact, a student's sense of accomplishment seems increased when she can apply skills and conceptsleamed earlier to anew, more complex problem. The application of these premises t o the design of the laboratory produces some striking differences in its structure. We shall describe here the structure of Explorations as i t has existed for the past two years. 1. If we are truly going to develop problem-solving skills in the

Laboratory, then we must allow students the luxury of being able to make mistakes, discover them, and correct them. That takes time. Realistically, it takes more time than the traditional 3-4-h lab period if students are to do anything of consequence. So Explorations is scheduled for nearly all day, from 10:15 a.m. to 5 or 6 in the evening. Three Explorations are scheduled each week. Each session is Limited to 20 students. 2. While it is important that each experiment involve important conceptsand techniques, it isequally important that there hea sense of exploration or adventure about it, which means that either the result or the pathway to the result not be given in detail. In some cases, that meansthat the answer is not obvious nor easilv found in a textbook. In others. there should he a variety of ways that the question raised by the experiment can be answered so that students are not doing everything in lockstep. 3. It is essential that students feel they have access to and can learn how to use modem equipment in their Exploration. Today that means a laboratory computer witbinput/output capability for use in experiments and high-level applications programs for controlling them and for doing computations and simulations. In faet, the computer has emerged as a significant integrating fadar in Explorations. We enjoy a splendid laboratory that we call the Computer Applications Laboratory (CAL) that is in a room of 4000 ft2and contains 16 AT&T 6310 computers, each with math coprocessors and a Metrabyte Dash-16 110 board and color CGA graphics. In addition there are fiveAT&T6300 personal computerswithmath coprocessor and one AST AT dass personal computer with EGA graphics. All systems are currently being upgraded with EGANGA monitors and grephics. The systems are all linked by a Starlan network using two AT&T3B2-400super minicomputers with a Unixoperating system. The networkalso has two impact printers, one laser printer, two HP six-pen plotters, and three bit pads for digitization. The consequences of this design have probably become apparent t o the reader. From a curriculum point of view, i t means that the laboratory takes on a significance in terms of allocation of student and faculty time that has not generally been so. In Everereen's case. the evolution of the laboratorv during the 15 years this course has been offered is revealing. Our current Exolorations has evolved from disci~linarvlabs that were an appendage to the lecture core to become the central oart of the course. Explorations now carries as much credit either the physics or chemistry or calculus part of the course. Explorations is a combined chemistry-physics laboratory that incorporates additional material from calculus and computer programming. From a faculty and staff point of view, labo&ry becomes a much more labor-intensive operation than has generally been the case.

The Computer In the Introductory Laboratory While the computer has assumed a central role in this unique laboratory, to be consistent with our premises, we place three restrictions on its use. First, it must serve as a means to an end and not just an end in itself. Second, the computer should not become a black box that performs operations and calculations that the student cannotcomprehend. Thus, a student should perform a calculation "by hand" and understand the vhvsicd and mathematical conhigher order algorithm that the cepts involved before using ; computer does for him. In this wav. the student learns to use the computer where it is most useful in science-for complex and repetitive calculations and for manipulating large data sets. Specifically, by the end of this introductory course, we want students to be able to use the computer as a scientific tool in four different areas: 1. as a word processor, 2. as a manipulator and plotter of numbers, 3. to make measurements and control experimentsin the lab, and 4. to make complex calculations and plots.

So, just as they would reach for a saw tocut a piece of wood or a hammer to drive a nail, by the end of the year they will instinctivelv use a word Drocessor (Word Perfect) with super/subscri& and ~ r e e charactek i to write a'report, a svreadsheet (VP Planner. similar to Lotus 1-2-3) to make aigebraic makpulations on and plots of data, an 110 lana w e (Unkelscone) to have the computer make difficult. repetitive measurements, and a high-level programming lan: guage (True BASIC or Turbo Pascal) to do a numerical integration or manipulate and display large data sets. And, just as important, for a simple calculation or an easy measurement they will know not to bother with the computer. Furthermore, to be consistent with the first premise upon which Exnlorations is based. we do not eive our students canned programs or procedures. They haie to devise them themselves. It is the discovery that they can devise ways to make measurements, control variables, and write their own programs that has made this laboratory so remarkable. Consequently we must teach students how to use these four ao~lications/promamminelaneuwes. We have develoved ou; own set of notes that &gr&eslearning these programming skills with laboratory explorations. There is an important and interesting distinction to be made between what we describe here and the use of the computer to facilitate laboratory instruction. Using the computer to simulate experiments and instruments are instances where the instructor is using the computer to make the teaching of these topics less labor intensive than the traditional laboratow. It is a form of comvuter-assisted instruction. It increases the productivity of ibe teaching staff. Not survrisinalv. the breakthrouehs in this area have come from lkge un&sities that have a s many students in introductory laboratory in a year as a faculty member in a small college might see in a lifetime. By contrast, in Explorations we teach students to use the computer so that they can be more productive in solving problems in the laboratory. This takes more faculty and staff time than the traditional laboratory, so our laboratory is more labor intensive. We believe that this extra faculty effort is worth it. Overview of Explorations We design Explorations to be a mix of computing and measurement, chemistry and physics, theory and experiment. Students have assigned desks and glassware in a traditional wet lab that is in a neighboring room. Movable tables with pendula, bomb calorimeters, pH meters, spectrophotometers. etc.. are set un in the CAL as needed. A small vacuum lin$ is &o availabie in the CAL. Students move back and forth between labs to verform their experiments and analvze them.

Students are introduced to laboratory procedures and application programs during the first half of an Exploration. During this time they are lead through an exercise that utilizes procedures new to them on a set of data or problem common to them all. In this way they learn new programming or lab procedures in a controlled way and by obtaining the "correct" results certifv to themselves and the facultv thatthey know what they are doing well. During the remakder of the Exnloration thev modifv or adant these nrocedures so that they are appficable to the t a s i or set df data thev are exolorine. w e do n i t require a hackground in computers for students entering M&M,and currently we find about half have little or no previous computer experiences. We begin gradually by introducing students to word processing during the first week. During the year they continue to use the word processor to write a weekly report. They then spend the next five weeks learning and using the spreadsheet. We have found the spreadsheet to be very effective for performing calculations on small data sets (