Pratyaksha darshan – The effectiveness of show and tell

Manek K Mistry

Many years ago, I worked as a part-time science and math teacher for fifth grade in a co-ed school in Mumbai. I was also completing a doctoral research project in botany at the time; teaching fifth graders till noon, working on scientific papers after that! Science fascinated me, I had little teaching experience and no training, but I had the backing of a principal who gave me a free hand as far as teaching science was concerned. The medium of instruction in that school was Gujarati till grade four and English from grade five, hence language was also an issue in understanding.

Most of my students were vegetarian and had not even touched an egg in their lives. It was while teaching biology that I realized the effectiveness of showing actual specimens – be it an egg, a mackerel (‘fish have gills’) or a small sand boa (‘snakes, like fishes, have scales’). After seeing something just once, they would remember easily. Language, however, remained an issue; I counted some seven different spellings of ‘gills’ in one test!

Incidentally, this also taught me how indoctrination and beliefs influence behaviour; students who would hesitate to touch an egg or a dead fish, handled the live sand boa (loaned by a natural history society) without fear. Their parents had told them not to touch eggs and fish, but had not thought of snakes!

It was while teaching some concepts in chemistry, however, that I was firmly convinced of the importance of demonstrating simple experiments. They had to learn that carbohydrates are made of three elements – carbon, hydrogen and oxygen. As I was wondering how to go about it, a simple demonstration in the Maharashtra State Board textbook (often overlooked and ignored) caught my eye. It was simple, but no teacher I met had actually performed it, at most they just talked about it. The demo involved burning a little sugar (carbohydrate) in a crucible while holding a glass plate over it. The sugar would char to form a black mass, something the 10-year olds found fascinating! That this black mass, similar to charcoal which they knew, is carbon was then an easy concept to remember. As the sugar chars, some liquid droplets collect on the glass plate held above the crucible. Let those who wish taste a few drops (ensure the glass plate is clean); it is a colourless and tasteless liquid, therefore most likely it is water. They had already studied that water is made of hydrogen and oxygen (H2O) and hence the constituent elements of carbohydrates were now clear. We performed this experiment over a small spirit lamp on the teacher’s table in class to good effect. I went on with my teaching and forgot about it.

Months later, after a parents’ day meeting, a mother of one of the students approached me and asked, “Sir, are you a scientist?” Surprised and, also a bit flattered, that this lady knew of my research work in botany, I said, “Yes, I am a research fellow, but how do you know?” “My son told me. He said our teacher is a big scientist, he turns sugar into coal and water!” she replied. It brought me down to earth. I realized that it was the burning of a tablespoon of sugar over a spirit lamp and not my scientific papers which made me a ‘big scientist’ in the eyes of these kids. I moved on to teach in college, but the kids kept in touch and would tell me that they used to pass in science without studying at home. I must admit that these were simple demos possible to show in class; higher concepts would require the infrastructure of a science lab.

I think the effectiveness of an actual demonstration does not diminish even now when so much information is available online. The importance of “pratyksha darshan”, actually meeting a person or visiting a place, has been accepted in our culture too. I went on to teach biology and botany in college, but this early lesson was never forgotten. Practicals and field excursions (just an hour around campus once or twice a month) became an integral part of my teaching.

The author is a retired faculty from the Botany Department of St. Xavier’s College (Autonomous), Mumbai. He can be reached at [email protected].

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