Introduction to The ‘why’ and the ‘how’

The art and science of designing experiments

Subha Das Mollick

Practicals and laboratory work are an inseparable part of any science subject. In the syllabus, 50 percent marks are reserved for practicals. But how are these practical classes held and what do students actually learn in these classes?

Typically, in a practical class, students are told what experiment to do and what result to expect. They follow a set procedure and do the experiment. Everybody in the class does the same experiment and expects the same result. In case of a physics experiment, if the student does not get the expected result, she tries to manipulate the data. Eventually the students record the experiments in a set pattern – Aim – procedure – observations – calculations – precautions – conclusion.

In a limited span of time, perhaps this is the best one can do. But this set pattern of laboratory work does not challenge the student’s creativity. The student does not get a scope to design a new experiment. Any student of science must understand the importance of experimentation in the development of science and should be able to design an appropriate experiment to test a hypothesis.

This section is dedicated to a few landmark experiments in physics that have revolutionized the way we understand the world around us. Each write-up explains how the scientist overcame technical hurdles of the day and succeeded in getting error free results. The teacher may find occasion to discuss these experiments in class to drive home the importance of designing a meaningful experiment. A well-designed experiment is also a work of art, a masterpiece to be appreciated. But the difference between Da Vinci’s Last Supper and Galileo’s experiment with falling bodies is that while the former is not meant to be replicated, the latter is meant to be replicated several times with the same results. The beauty of a work of art is in its uniqueness. The beauty of a work of science is in its replicability.

The stories of unravelling the truth through each of these experiments are also gripping stories, nothing short of the mystery stories children are so fond of hearing. So the special classes on these experiments can be high on entertainment value and take away the tedium of a routine class.

The author is the secretary of Bichitra Pathshala, an organization that promotes learning with moving images. She is also an associate director at iLEAD Institute, Kolkata. She can be reached at

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