. By Chung Chieh (e-mail), Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L3G1

3. Computer Aided Chemistry Tutorials

Computer Assisted Chemistry Tutorials (CACT) were instructions managed by a browser-like program called Resource written in the Quick Basic language. The CACT files resided in a server of local area network (LAN) of personal computers. Students accessed the CACT system from any workstations of the LAN in a disk operating system (DOS). The DOS CACT system was in operation between 1980s and 1998, but we began to convert the files into Internet documents in 1996, and placed them on the Internet in 1997. Students accessed either version in 1997-1978, but only the Internet CACT was maintained and supported by the Fall of 1998.

Both the DOS and Internet versions follow the same design, and the design of the DOS CACT is described in this section.

<= Esc

An acid is a substance
that dissociate into ...
when dissolved in water ...
Resource starts by displaying a Menu, which is equivalent to the table of contents in a textbook. Each item on the Menu is linked to an Instruction file. A user moves the hilighted choice (base) from the Menu by using appropriate keys that are usually used to control the cursor movement. A user can move one item or 20 items at a time in either direction by typing an appropriate key. Typing any key will move the choice one item at a time in the forward direction. By pressing the Enter key, the Instruction file linked to the highlighted (base) item of the Menu will be displayed. When a user depresses the Esc key, the Menu is displayed for the user to make another choice. At that time, we had to show students where the Enter, Esc, PageUp, PageDown and the arrow keys were on the keyboard, because most of them had not used a PC before.

At the start, the DOS CACT was a flexible system. Users had to keep track of the documents they have read and know what they need to study. In later years, the CACT automatically recorded a history for each student to help the user to keep track of his or her study. My own CACT history was the first item on the Menu, and the History showed the date and the title if and only if he or she had answered the Dialogue questions. This file resided in the users private account called CACTHIST, and the contents were updated each time.

A CACT Subject
What is an acid?
What is HCl?
Why is HCl an acid?

An acid is a substance
that dissociate into ...
when dissolved in water ...
Demonstration         Quiz
Which is produced by
an acid?
H3O+     H2O
OH-       .OH
Every subject on the Menu of the CACT system has four potential components: Instruction, Dialogue, Demonstration, and Quiz. Unfortunately, the DOS based technology enables only one of these to be displayed at a time. By typing appropriate keys, the user can go from one component to another. All subjects have the Instruction and the Dialogue, but some have all four components.

The Instruction and Dialogue are handled by Resource, which is linked to Demonstrations via the Menu. Quiz is handled by a separate program to conduct tests and record marks. They all work together as a single system.

The strategy for CACT may be applied to any subject or course. A considerable effort was required for preparing the content and we had a full implementation only for the the large first year chemistry courses.

When a resonable amount of content were implemented, we asked about 120 Chemistry-Major students to try the preliminary version. Then we released it to about 800 students who are taking the freshman chemistry courses. These students are from various programs in the Faculties of Mathematics, Health Studies, and Sciences. The engineers at the University of Waterloo offer their own version of a one-term freshman chemistry course, dealing with equilibrium and stoichiometry.

The CACT worked well with the local area network (LAN) called JANet, and University wide network systems called WatStar (DOS and Window 3.1 operating system), and later Polaris (Windows 95 being the default operating system).

Starting in 1997, students entering university did knew what DOS represented. To them, the Windows system is how computers should work. Changes to CACT were unavoidable and some possible changes were to:

The advantages and disadvantages of each of these possibilities have been carefully considered in view of our strength and resources.

Since web browsers have been distributed free of charge, and they have been readily available at the university work stations (computers), we decided to make the CACT available on the Internet. The conversion was underway in 1997. We tested it extensively with browsers abailable on the University computing facilities.