computer ~ e r i e45 ~,
edited by Eastern
Michigan University.JOHN Ypsilanti, W.MMOORE I 48197
Using the Computer for Pre-Laboratory Quizzes that students have preiaied t h e m s e l ~ e s i d e ~ u a t e lfor y laboratorv. One is desiened for introductory chemistry, the other date any sequence of experiments a t any level.
Enhancing the Laboratory Experience in Introductory Chemistry with Apple-based Pre-lab Quizzes Nancy H. Kolodny Rachel Bayly
Wellesley College Wellesley, MA 02181 Anyone who has taught an introductory chemistry lahoratory section can tell you that the experience a student has in lab is very dependent on how well heishe has prepared. In most courses students are urged to prepare by reading the lab manual, reviewing related concepts from lecture, and becoming familiar with the techniques and manipulations of the experiment, but few students actually do so. At Wellesley we soueht an effective. non-threatening way to ensure pre-lab an Apple-based quiz for each experiment. This methodhas proved to be an effective and enjoyable means for ensuring thorough lab preparation. Some pre-lab CAI materials have been described before in THIS JOURNAL^, hut these are available on a limited basis since they are written for the PLATO system a t the University of Illinois. Textbook publishers are beginning to market personal computer-based laboratory reparation materials designed for courses which part&nt willing to-purchase an Apple computer and its PILOT software, because quizzes can he created in a reasonable amount of time by a student programmer, and because it requires students to pass a quiz prior to each lab session. The laboratory portion of introductory chemistry a t Wellesley is an integral part of the course. Students work in the lab approximately 3% hours once each week for twelve or thirteen weeks. The experiments range from a seveu-week project involving the synthesis, purification, qualitative and quantitative analysis, and measurements of physical properties of transition metal c o m ~ l e x e s to ~ , one- or two-week hydroxide ion. Students receive detailed written descriptions E ~ u 57, c 196 'Moore, C., Smith, S., and Avner, R. A,, J. CHEM. (1980).
Loehlin, J. L.. Kahl, S. B., and Darlington,J. A,, J. CHEM. Enuc., 59, 1048 (1983).
896
Journal of Chemical Education
of each experiment which discuss both theoretical and practical aspects. Laboratory techniques such as the use of analytical balances and volumetric glassware are taught as needed and are cumulitive through the year. Each student keeps a laboratory notebook which is graded a t regular intervals by her lab instructor. Althoueh a maior comuonent of student success and satis.
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encouraging preparation by administering written quizzes a t the beginning of each lab meeting, but we preferred not to increase the anxiety level in what is, for many students, already a trying experience. Instead, we designed and created a set of 22 pre-lab quizzes which are available to all students on diskettes a t Apple computers located in the Science Library and in the laboratory area. Each week, before coming to lab, students can take the appropriate quiz as many times as necessary to achieve the required score of 4 out of 5. We chose the Apple computer as the vehicle for our quiz system because of the availability of the PILOT language with its color graphics and music capabilities and its ease of use as a testilesson authoring language. The documentation for PILOT meets Apple's generally high standards, although there are a few points of confusion and a few minor bugs. We chose to use the Apple rather than to add color graphics to our mainframe DECsystem-20 computer largely because of cost. Furthermore, all Wellesley chemistry students already use the DECsystem-20 and we saw an advantage in introducing them to another type of computer. Instead of merely testing students on lah-related material, we use the quizzes as an opportunity to reinforce the concepts needed for lab. For example, one of the most universally important quizzes simulates in detail the use of an analytical balance. (The PLATO CAI materials mentioned above include a similar module). Each quiz is a self-contained unit with various types of questions, including multiple choice, calculation, and short answer. If the student answers a question incorrectly, the program branches to display pedagogical material designed to help her figure out the correct answer. This material changes for each successive wrong answer, and after a maximum of three wrong answers is a statement and explanation of the correct answer. Credit for a correct answer is given only if the student answers correctly the first time. The quizzes are short enough that taking them more than once is not very painful. The time a student spends a t the computer in order to pass a quiz varies dramatically depending upon whether or not she has studied her lab manual heforehand. A prepared student spends an average of 5 to 10 minutes; an unprepared student may spend up to 30 minutes, repeating the quiz until she passes. The quizzes are humorous and include dynamic graphics so they are entertaining as well as instructive. They were written by an articulate, artistic student programmer with a good sense of humor, who also had experience in the course for which the quizzes were intended. She spent ten weeks, forty hours per week during a summer, and approximately 200 hours during the academic year
creating and maintaining the quiz system. Part of her time was spent learning Apple PILOT. T h e quiz system keeps a record of the student's name and score each time she tries a quiz. At the end of each trial she is toldher score and whetherbr not it is adequate for her to be admitted to lab. By giving the appropriate password a t the beginning of the quiz, instructors can access the accumulated student records sothat they can make sure that everyone in their lab sections has passed. Students who have not passed are sent back to the computer to try again. The results of evaluation questionnaires filled out by 160 students and 8 lahoratory instructors demonstrated the success of the quizzes and helped elucidate the reasons for their success. We found that the quizzes 1) helped students understand what they were trying to do in lab
hy forcing them to read the manual and reinforcing the ideas presented in the manual, 2) provided practice calculations and helped relate them to the lab . . work, 3) were fun (in part because they were Wellesley-specific),and 4) were comprehensible and easy to use. A major side benefit of creating the quizzes was that ambiguities in the format and language of our lab manual became annarent. causine us to rewrite most of it. Because the individual quizzes are directly tied to the manual, they are useful to other institutions onlv if thev also adont our exueriments.
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as may he a diskette which contains an explanation of the quiz
commercial source
A Computer-based Pre-laboratory Quiz for Organic Chemistry Ronald Starkey' David Kieper2 College of Envimnrnental Sciences University of Wisconsin-Green Bay Green Bay, W I 54301 We have developed, and utilized during the 1980-81 and 1981-82 academic years, a computer-based pre-laboratory quiz (PLQ) for organic chemistry." Objectives The objective of the Pre-laboratory Quiz system is to help optimize each student's educational experience and safety in the lahoratory by assuring that students come to the laboratory sessions adequately prepared. We believe an adequate lahoratory preparation should improve a studentis understanding of and efficiency in performing the lab experiments and, in addition, increase lahoratory safety. Anxiety toward the laboratory should be reduced when students know they are adequately prepared before coming to the laboratory session. The objective of ensuring students are adequately prepared for laboratory experiments can he achieved by testing the studentsprior to the lab session and requiring a demonstrated competency level before the experiment can be performed. The computer-based quiz efficiently utilizes faculty and staff time and allows the student the freedom to be tested a t hisher convenience. The computer package we developed allows students to take the PLQ during the university's computer center hours, any day prior to each week's laboratory session.
System Format The PLQ format consists of five multiple choice questions dealing with the theory, methodology, and safety precautions of the experiment to be performed that week in the lahoratory. Each PLQ was designed to test the students' preparedness to undertake a particular lahoratory experiment. T h e package is written in Standard Fortran and used on the University of Wisconsin-Green Bay's medium size mainframe computer (a Xerox Siema 6 ) . Our choice of a mainframe comuuter. rather than a mTnicomputer, is based on the need for Eonsiderable text and data storape and t i ~ h securitv t of the - cauahilitv Computer package. The PLQ svstem utilizes an interactive mode and thus it can he used h i students with no prior computer experience. We desianed the svstem to be accessible only via the computers CRT (cathode ray tube) terminals so a i r i n h u t is not available to the students. Each PLQ, with the exception of the Laboratory Safety PLQ, consists of five multiple-choice questions. The five questions are chosen from five different categories. Each category contains from one to five available questions. When a student takes a particular PLQ helshe is presented with one question chosen a t random from the questions available in each category. The categories in a typical PLQ are 1) Theory of the Experiment; 2) Laboratory Methodology and Procedures; 3) Calculations; 4) Product Isolation and Identification; and 5) Lahoratory Safety and Precautions. For each of the five multiple-choice questions given, the student resnonds hv" kevine - " in the letter corresuondine to what hehhe believes is the correct answer. 1f there&nsek correct the computer retains the question display and also displays "CORRECT" and provides a "correct response comment." This comment is designed to reinforce the correct response or provide additional informationto the student. If the student's resuonse is incorrect. "INCORRECT is disulaved . . and an "incorrect response comment" is presented. Features of the system The auorouriate auiz must he successfullv comnleted orior to the s & k e k s admission to each laborat&y session. Astudent may take thePLQ as many times as is necessary to "pass" the quiz. Passing the quiz requires answering correctly all the questions presented. A student who has not passed the PLQ is not admitted to the lahoratory session. The successful completion of a PLQ is noted in the "STATUS" file as "completed." The "status" file printout is retrieved hv the lahoratorv instructor urior to each lahoratorv session. he "status" fileindicates forkach student in a section one of the following: "attempted", "not attempted", or "completed". A statistics file is also kept for each student and each question in the PLQ. The information available includes the terminal time and the number of attempts for each student. We limited the PLQs' to five categories in order to keep the terminal time for each student to a reasonable length. During the 1981-82 academic year, we found the average-number o j attempts necessary per student to pass a PLQ to he about three. 'l'hi, vorre:ponds 111 ,111 a t e r x c 11 rmillnl Irunllw1, rime u~idcrn ~ n niinut~..< e per stutlc~it. \ n auditio~ialfwtl.re i i rhc PI.0.i w " t c m n.t. I;lu~idu ~ f t d was a "mailbox". The mailbox is a means by which messages
Presentedat the i8ist National Meeting of the American Chemical Society, Atlanta, GA, March, 1981. Associate Professor of Chemistry. Software Manaaer. University of Wisconsin-Green Bay Computer Services. Supported by a University of Wisconsin Undergraduate Teaching improvement Grant.
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Volume GO
Number 10 October 1983
897
