During my days as a teaching assistant (TA) at the Michigan Technological University, I usually taught first year undergraduate students in the lab. First year chemistry was a compulsory course for all students, therefore the strength of the class was anywhere from 500 to 600. Most of these 500 odd students were engineering majors and had very little interest in chemistry. They went through the motions because it was a required course.
My job as the lab TA was very simple and straight forward; I had to guide the students through the experiment in the three hour session and assist them as and when required. I was more of a facilitator than an instructor, except during the first 15 minutes when I explained the entire experiment to them.
There was one experiment in the course about verification of “Beer’s Law”. It was a simple experiment where a series of coloured solutions of increasing concentration was prepared and their absorbances were measured and recorded. A graph of absorbance v/s concentration was drawn, which resulted in a straight line with a positive slope. Then the absorbance of a solution of unknown concentration was measured and the corresponding concentration was derived from the graph drawn earlier.
A common question asked by students during this experiment was “Why do we have to plot absorbance on the ‘y’ axis and concentration on the ‘x’ axis? Why not the reverse?” I answered this question in different ways, always explaining how absorbance was measured against concentration and concentration was the parameter under our control and so on. The students accepted my answer but never seemed convinced.
Then one fine day when I was asked the same question, I tried a different tactic. I said “Look, the graph is a straight line whose equation is y = mx + c. Here, concentration is the independent variable (x) and so it goes on the x axis, absorbance is the dependent variable (y) and so it goes on the y axis”. The student nodded his head with a smile and said, “That actually makes sense”.
All my words of explanation made no sense earlier because these kids spoke the language of mathematics. I danced a little victory dance in my head excited about cracking this code of communication (it took me two semesters to do it though!). Needless to say I used this language from then onwards and saw more nods and smiles than frowns and blank faces.
This was the time I realized that teaching is not only about communicating what one knows, but communicating in a language that students can relate to. To this day, I have not mastered this art but I am always conscious of it. No matter how many times and how many students I teach the same topic to, there is always something new for me to learn from their responses. This is probably the reason why I don’t get tired of teaching.
– Dr. Soumyashree Sreehari