Networked Instructional Chemistry: Using Technology To Teach

Information • Textbooks • Media • Resources

Networked Instructional Chemistry Using

Technology

To

Teach

Chemistry

Stanley Smith and Iris Stovall School of Chemical Sciences, University of Illinois, 600 S. Mathews, Urbana, IL 61801 Networked multimedia microcomputers provide new ways to help students learn chemistry and to help instructors manage the learning environment. This technology is used to replace some traditional laboratory work, collect on-line experimental data, enhance lectures and quiz sections with multimedia presentations, provide prelaboratory training for beginning nonchemistry- major organic laboratory, provide electronic homework for organic chemistry students, give graduate students access to real NMR data for analysis, and provide access to molecular modeling tools. The integration of all of these activities into an active learning environment is made possible by a client-server network of hundreds of computers. This requires not only instructional software but also classroom and course management software, computers, networking, and room management. Combining computer-based work with traditional course material is made possible with software management tools that allow the instructor to monitor the progress of each student and make available an on-line gradebook so students can see their grades and class standing. This client-server based system extends the capabilities of the earlier mainframebased PLATO (1) system, which was used for instructional computing. This paper will outline the components of a technology center used to support over 5,000 students per semester. Instructional Computing Environment To have an impact on learning, instructional software should be complete enough that it represents a major part of the course. However, instructional software tends to be a collection of fragmented programs on single topics, which is difficult to combine to form a comprehensive component of a course. Even when software is available to make an impact on the way a class is taught, software is not enough. Making the transition from traditional methods to new ways of teaching and learning must be easy and effective. It must be easy for instructors to assign and make available to students new programs as they become available. It must be easy to monitor the progress of students in several courses. It must also be easy for students to do their lessons and receive credit for their work. While the number of students who arrive with no computer experience is decreasing, there are still students who are anxious about using computers to learn chemistry. It must be as easy as possible for students to focus on the content of the lessons, and not on learning how to load computer programs. Other courses at the college level are designed to teach the fundamentals of computing.

courses that use lessons provided by this technology center. As shown in Figure 1, students double click the Signon icon to receive course credit for their work; or they can choose Browse, Molecular Modeling, or Netscape, which allows them to explore programs without receiving credit. No written instructions are provided or needed. The desktop icons on each machine and the programs they point to are stored on the server so that new programs can be added and old ones removed when needed. A consistent desktop with instructions on the screen saves around 3000 sheets of printed paper instructions and abrogates the need for continual verbal repetition of instructions. Control of desktop appearance is possible using Microsoft Windows95 operating system. Management System When there are many classes and many different instructors who may be using two or three different kinds of chemistry lessons or activities, a major problem is not only providing software lessons for students to use, but allowing the right students access to the right lessons and grades. This problem has been solved by development of a special on-line classroom management system (2), which manages record keeping for students and instructors. This management system has four major functions. First, it handles the task of logging a user onto the lesson system. When a user types in his or her name the management system identifies the user as either a student in the course or as the instructor, based on a database of information (Fig. 2). Once the type of user is identified, the management system then provides an appropriate set of options for that type of user. Second, if the user is the instructor, options to assign lessons for the class, add or change the roster, review progress of each student, and add new les-

Consistent Student Interface All students—whether freshmen, sophomores, or graduate students—begin with the same initial desktop. Students who learn to sign on their first semester use the same signon procedure for all subsequent chemistry

Figure 1. Students select the type of instructional activity from the main index to the network.

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sons to the index are presented from within the management system (Fig. 3). At the beginning of the semester the instructor assigns lessons by selecting them from a catalog of available lessons, as is shown in Figure 4. The selected lessons automatically appear on the list of required lessons that a student sees when he or she selects a course and types in a name and password. The management system can accommodate different courses and instructors using some of the same lessons, or completely different ones. Having one program that manages access to all lessons and records which lessons have been completed greatly simplifies the task of assessing progress. Although instructors can add and delete students from the roster during the semester, they are not required to type in the names of all the students in their classes. The class roster is entered by importing the names from the University computerized registration system. Once the roster is in place, students can sign on to the system with their names, social security number, and a password that they select. This gives them access to the lessons assigned by the instructor. Students are never aware of the instructor’s options. They only see the list of assigned lessons. Third, the management system automatically records the lessons completed by individual students and the time spent working them. The record of completed lessons can be viewed by the instructor at any time. In the current semester, over 5,000 students in 11 different courses are registered with the management system. Finally, the management system helps organize scores from course activities such as exams, homework, and quizzes.

Figure 2. Users type their name and course name to gain access to lessons on the network that are done for course credit.

Gradebook Because some of the graded work associated with a course is not performed on the computer, the management systems incorporates a gradebook (3), which stores all scores including hour exams and laboratory reports in addition to the computer-based work. Instructors can, of course, enter, see, and change scores and assign course grades. Teaching assistants can see or edit scores for the students in their sections, at the discretion of the instructor. Students can see their own scores as well as view general graphical information about their rank in class. A sample screen from the gradebook is shown in Figure 5. Hour exam scores and computer lessons completed are entered electronically into the gradebook, which eliminates errors associated with scores typed in by hand.

Figure 3. Instructors set up the course for their class by adding names to the roster, reviewing individual student progress, and selecting lessons to be done by the students.

Classroom The design of the room where most students access the computers is an important component in creation of an effective learning environment. It is desirable to include study tables and books and to assign teaching assistants to be available to answer any course-related questions. A location was selected that has windows and glareprotected lights so the room is a bright and attractive study area. The room is supervised by a full-time professional who is qualified to deal with both the computer technology and tutoring of individual students in chemistry. During a typical week in the fall semester, 3,000 to 5,000 students use the Learning Center for accessing lessons or consulting with teaching assistants. During the spring 1994 semester, use of the networked computers was in excess of 12,000 hours.

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Figure 4. Lessons on which students are to work are selected from the catalog.

Journal of Chemical Education • Vol. 73 No. 10 October 1996


If all of the machines that students use to access the instructional material are networked to a server that stores a common data base of names, courses, lessons, and grades, then students can use any machine on the network. Any computer on the network can access lessons for any chemistry course, so students are not restricted to just one machine that contains the information about their course and lessons. To do this, a 10BaseT, 10 Mbps ethernet local area network was installed. The network, outlined in Figure 6, supports 3 servers, 87 IBM personal computers in a chemistry learning center, 44 machines for online data collection in the laboratory, 5 computers for multimedia presentation in quiz sections, 4 machines for management, and over 200 computers at other campus locations. Since all of the lessons and management software is located on the servers, updates and additions are easily made. Only one or two servers need to be updated, instead of more than one hundred individual machines. Each client machine has MSDOS and Microsoft Windows running locally. An ethernet board is installed in each client machine along with networking software to enable it to connect to the server. The computers in the chemistry learning center are used only for chemistry lessons and data analysis. Students have other options on campus for word processing and sending e-mail. When students use the chemistry learning center computers they can only run the lessons provided. Default options that are present in the Windows95 interface, such as the control panel, have been removed for all student logons. The absence of items such as control panel prevents accidental or intentional changes to configurations. It is very difficult for students to erase files from the client machine hard drive or to copy files to and from either the client or the server. The opportunity for introduction of computer viruses onto the network is minimized. One advantage of a networked computer-based instructional system is that students can work whenever the computer rooms are open, rather than adhering to a restricted class schedule, and they can work at their own rate. However, there is a tendency for students to put off doing assignments as long as possible. This results in significant numbers of students waiting for a free computer just before exams and scheduled due dates. To avoid installing sufficient hardware just to handle these peak loads

the local area network in the Chemistry Learning Center was interfaced with local area networks at other computer sites on campus. As a result, students can do their chemistry laboratory lessons, for example, in the Undergraduate Library. The only real restriction on how many students can access the chemistry servers is the bandwidth of the network connection. The computer sites on this campus that have a 10 Mbps ethernet line to the chemistry servers can run the software at acceptable rates. Dialup modems, at current baud rates, are too slow to be useful with these interactive, multimedia-based lessons. Previously, many of the chemistry lessons available to students required videodisc players to deliver the video. The videodisc-based lessons (4) have now been converted to digital video (5) so that they can run on the network. All the lessons, including the video, run from the hard drive of the server. This removes the requirement for a videodisc player at each machine and the special hardware to mix analog video with computer graphics. The choice of a digital video technology to replace the videodisc video was dictated by the limitations in bandwidth of the network and the need for the lessons to run on student machines without any special video playback boards. The digital video plays back using IBM Photomotion™ software at a screen resolution of 320 ∞ 200 pixels in 256 colors. The video occupies around one quarter of the computer screen, and about 80 kbyte/s is required for fullmotion video. Because of the large amount of data required to support full-motion video, the number of simultaneous student stations which can run on a single 10 Mbps line to the server is limited to about 20 to 30 machines. However, providing multiple full-duplex lines to the server, as shown in Figure 6, increases the effective bandwidth of the system from 10 to 40 Mbps and makes it possible to run 80 to 100 machines without delays. This is accomplished by using load-leveled, full-duplex Ether Streamer cards in Microchannel™ bus servers connected to an ethernet switching hub. The switching hub routes data to the appropriate student station through the 5 wiring hubs. As many as 24 student computers can be attached to each wiring hub using twisted pair (10BaseT) wiring. The choice of a server for presenting digital video is very important. A server with a bus that can transmit data quickly is desirable. The bus can limit the speed with which data move to the ethernet card. Our data show that a server with a faster Microchannel bus but with a slower

Figure 5. Grade distribution from the on-line gradebook.

Figure 6. Network configuration.

Networking


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(486, 33 MHz) processor will outperform a server with a fast (486, 66 MHz) processor but with the slower ISA (Industry Standard Architecture) bus. A Microchannel or PCI bus server is needed to transfer video data at acceptable rates to large numbers of students. The choice of network interface cards—in this case, ethernet cards—also helps determine whether the video appears smooth or jerky. The purchase of more expensive 32-bit ethernet cards for the server increases performance. Since the last-accessed files and their directories are kept in the server’s memory, servers need to have a large amount of memory if many different lessons are used at once. Sixty-four megabytes of memory allows a server to have more than 100 files open at once for fast access. The type of computer used for student stations is not as important as the configuration of the server. Student stations are 33- and 66-MHz 486, and 75-, 100-, and 133-MHz Pentium microcomputers with ISA or PCI bus, 16 MB RAM, and 16-bit ethernet cards. It has been possible for over 100 students to be signed on and performing lessons at once with a single 66-MHz MC server with 64 MB RAM. Of course, not all 100 students are playing video files at once and some may be engaged in activities that don’t use video, such as the gradebook. With about 180 students running lessons on a single 66MHz MC server, mean CPU utilization is under 20%. Network Operating System software allows an administrator to control students’ access to files and lessons on the server so that unauthorized users cannot view or change sensitive grade files. Novell Netware 4.1 in Netware Directory Services (NDS) mode is used as the Network Operating System. NDS makes it easy to share the student load between multiple servers because users can be automatically authenticated on each server with a single login. Consequently each server appears to be just another disk drive. Netware 4.1 can also facilitate transfer of video files from the server to a student computer by sending consecutive pieces of the video file without waiting for an acknowledging signal from the student computer. This so-called packet burst mode should be enabled on a Netware server that delivers digital video. When the student computers are first booted, each machine logs on to the network using a Novell login specific to that machine. If rights to additional files and directories are needed, our software automatically performs a new Novell login in the background so that students can use the instructional software they select from the desktop in Figure 1. Each type of use results in a different internal Novell login, which facilitates monitoring and tracking system use. With grades for over 5,000 students stored on the server, automatic backup is essential. At present, either of two servers can deliver all of the lessons in case one of the servers malfunctions, although the load is normally spread between the two servers. In addition, tape backups of the entire system and an additional tape backup of grade information is made every day. The goal is to be able to keep running even if there is a massive hardware failure. Application Software Interactive digital video lessons are being used to replace up to half of the traditional laboratory work for the first semester nonmajor general chemistry course. Students spend alternate weeks doing wet laboratory experiments. The computer lessons (6) (Fig. 7) cover chemical reactions, chemical equations, solubility, equilibrium, oxidation and reduction, gases, acids and bases, reaction 914

Figure 7. Digital video laboratory simulatory lesson.

Figure 8. Classroom multimedia presentation.

Figure 9. Students practice multistep synthesis by selecting starting material and reagents for each step.

rates, orbitals and electrons (7), transition metals, heats of reaction, and batteries. This type of instruction extends the content of the course by allowing students to interact with video-based experiments that are difficult to do in traditional laboratories and which reduce student exposure to potentially hazardous materials or procedures. Students may repeat lessons as often as they want, so time-limited laboratory work becomes a competency based exercise.

Journal of Chemical Education • Vol. 73 No. 10 October 1996


Computers are also used to enhance wet laboratory experiments by allowing students to collect data on-line, store it on the server, and review it later. Some laboratories are equipped with interfaces such as Vernier Software’s MultiPurposeInterface, which allow students to collect and analyze data and are part of the network. In the laboratory students log into the network and run their experiments. The data are automatically stored on the server for each student. After leaving the lab, students can access their work from any machine on the network to review the data, do calculations, and print data, charts, and graphs for reports. Multimedia technology is extended into the classroom (8) by equipping small classrooms with networked computers and large-screen monitors. Small lecture–discussion sections with around thirty students per section are taught by teaching assistants who augment the traditional blackboard and chalk presentations with multimedia, including both still and full-motion video images of chemical reactions, demonstrations, and examples (Fig. 8). The lessons used in the classrooms also present concepts and provide fully worked out example problems. The use of these lessons by teaching assistants ensures that all students receive similar, high-quality presentations. After class, students can access the same material from one of the networked computers. Traditional cryptic lecture notes are replaced with easily accessed multimedia presentations that include all of the material covered in class plus remedial material and additional examples. Networked lessons are also used as electronic homework. In organic chemistry (9) this takes the form of tutorial lessons with extensive practice problems on alkanes, conformational analysis, chirality, alkenes, arenes, NMR, IR, alcohols, aldehydes, ketones, carboxylic acids, and amines. For example, in multistep synthesis problems (Fig.

9), students select a starting material and the reagents for each step in the preparation of a target molecule. Electronic homework provides the advantage to students of immediate feedback while alleviating the problems of scoring large numbers of written assignments. The system automatically records the completion of the assigned work. Graduate students use the network to access NMR spectra, which must be analyzed with networked software, printed, and turned in as homework (10). Lessons are also available (11) as a prelaboratory for some of the beginning organic chemistry laboratory experiments. Topics include melting points, distillation, extraction, and qualitative organic analysis. Summary The integration of computer-based instruction, multimedia classroom presentations, computerized laboratory work, and electronic homework with an on-line management system and gradebook increases the quality of instruction and makes it easier for the instructor to teach with the computer than without. Literature Cited 1. Smith, S. G.; Sherwood, B. A. Science 1976, 192, 344–352. 2. Kornet, J. L., III. Falcon Software, 1 Hollis Street, Wellesley, MA 02181; and Smith, S. G. University of Illinois. 3. Smith, S. G.; Stovall, I. K. Department of Chemistry, University of Illinois, Urbana, IL 61801. 4. Smith, S. G.; Jones, L. L. J. Chem Educ. 1989, 66, 8–11. 5. Jones, L. L.; Smith, S. G. Pure Appl. Chem. 1993, 65, 245. 6. Smith, S. G.; Jones, L. L. Falcon Software, 1993. 7. Gammon, S. Department of Chemistry, University of Idaho, Moscow, ID 83843. 8. Stovall, I. K.; Wilson, R. B. Department of Chemistry, University of Illinois, Urbana, IL 61801. 9. Smith, S. G. J. Chem Educ. 1970, 47, 608. 10. Petillo, P. A. Department of Chemistry, University of Illinois, Urbana, IL 61801. 11. Smith, S. G. Falcon Software, 1993.


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Networked Instructional Chemistry: Using Technology To Teach

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