I cannot claim my introduction to the Pathway Method to have been inspired by Polya or Piaget. As a high school student, I enjoyed working out a given problem by as many methods as I could devise. A decade later, teaching high school and university, I developed the Pathway Method. Briefly, I believed this was a breakthrough, a discovery in teaching methodology. Then I came across a British textbook using this method, so most probably it was in use in many places.

Further years of teaching and writing problems for textbooks, however, led me to what I would describe as a refinement of the Pathway Method. I refer to what I have called the "tunneling method". Again, I am not claiming discovery rights, but I did develop it from my own pondering on why some students just can't think their way through a problem involving several steps. The tunneling method has been discussed in two of my textbooks (2, 3).

The strategy is to start from each end, and link somewhere in the middle, rather than working backwards, stepwise from the objective or target to the data. I believe that this approach has several advantages:

It helps save the struggling student from getting overwhelmed and lost in the problem.

It helps to avoid time-wasting side tracks.

It is more efficient overall for a variety of students.

As an analogy, it is suggested that solving the problem is like getting from one side of a mountain to the other. Climbing over the top is not the easiest or most efficient way, if there already is a tunnel through. Just as the engineers building the tunnel plan to start at each end so that the excavators meet in the middle, so the student unravels the problem by starting at each end and linking up. Once the sequence of steps has been identified, the problem is solved by working forwards from the data to the target, as shown in the example below and in Figure 1.

Problem: A moth of mass 1.10 g consumes 55 mL of oxygen (at 27 °C and 1.00 atm) per hour of flight. If glucose supplies the energy, what is the minimum mass of glucose that the moth must gather from plants for each hour of flight?

C₆H₁₂O₆ (aq) + 6O₂(g) → 6CO₂(g) + 6H₂O(l)

Figure 1. Tunneling method applied to the chemistry problem in the text.

My approach has developed from "hands-on" experience rather than an in-depth study of learning theory, but it would be interesting to see an evaluation of the tunneling method.

Literature Cited

1. McCalla, Joanne. J. Chem. Educ. 2003, 80, 92–98.
2. Smith, Alan; Dwyer, Christopher. Chemistry About You; Nelson: Melbourne, 1986, 1988; pp 190–191, 201–202.
3. Smith, Alan; Dwyer, Christopher. Key Chemistry, Book 1; Melbourne University Press: Melbourne, 1991; pp 463–464.

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