The original problem that this teaching unit set out to solve was how to address the student’s need for intrinsic motivation to studying chemistry and at the same time to introduce students to theoretical chemistry. The needs of the academy must be balanced against the needs of the students as novices. The balancing act is the art of teaching. Elegant displays of theory in beautiful text books with lavish color photography and applications to the real world and careers is, in my view, insufficient. Chemistry continues to appear to be terribly abstract and flunks out poor students with the greatest of ease. Going back to the days of kitchen chemistry when this was not so, is not an option, not merely because it was expensive, dangerous and environmentally irresponsible, but though it wonderfully motivated students, it suffered from excessive mindless description signifying very little. The Linus Pauling revolution that put theory into the heart of the syllabus has given order but has thrown the baby out with the bathtub from my point of view as teacher. Does the above pedagogy of experience-based chemistry using an analysis given by the scientific method in terms of learning theory do better?
Clearly the strategies outlined above are only a possible exemplification of what could be done, It is limited to one particular context that in itself could be used to teach more theory in high school chemistry. Much more could be made of the opening class, ‘From oceans to clouds’. There is no discussion of rates at which water molecules move in the hydrological cycle, expecially as water evaporates off the ocean. Calculations can be made from experiments conducted in class. For the most part the choice of experiments and theory explored has been dictated from the standard curriculum in Chemistry.
One important way this unit could be adapted is to make it more intentionally interdisciplinary. The hydrological cycle is taught in biology, environmental studies, earth sciences and possibly as a context for mathematics and physics. The academic interests of these disciplines would open up the unit and create new emphases that would dictate the inclusion of many more interesting explorations.
A criticism that I would expect would be that the mini-bites of theory used are truly that—very small, or that in some instances, theory is presupposed (for example the class on sewerage treatment and analysis of ions). To counteract that objection, I would point out that the unit presupposes an introductory unit in which the basic language and core concepts of chemistry have been introduced. One cannot teach hydrogen bonding even in the simplistic way taught here, without having dealt with the structure of the atom. On the other hand, students do not remember the language of chemistry without continually using it. The scientific method cannot be taught in the abstract. It can only be acted out for it to really to mean anything—hence my contention that we need to make it central and not extraneous to the manner in which chemistry is presented. If less theory gets covered, so be it, but actually I think the opposite happens. Once the content of chemistry is introduced in the manner used in the above unit, it enormously speeds up both the understanding of the content, and why it is included in the syllabus and it makes application in problem solving that much easier. This unit must be used as part of a complete syllabus in which key concepts in chemistry are continually recycled throughout. Mak ing sure one is not out of step in the development of concepts is part of the skill of teacher planning.
In the final analysis the proof of the pudding is in its eating. From this teacher’s point of view, it dramatically raised the level of active and ready participation from the students. Since I introduced the method towards the end of the year it was not easy to have an overall perspective on success. I had frustration in getting students to hypothesize along with me. It was hard to wean students from following ditto sheet instructions for labs. The last of the experiments on thermal heating I made up in my head and I really did not know what to expect. All of the experiments otherwise are adaptations of remembered experiments from the past or simplifications of experiments, for example, of those in the textbook lab manual. The ideas presented here then are tentative and intended to inspire experimentation in technique of instruction based upon deeper reflection upon what it means to learn from experience in the class room, for both teacher and student.
