The Scientific Method

According to a classic description of the scientific method due to Karl Pearson this method is marked by careful and accurate classification of facts and observations of their correlation and sequence. In many instances — especially in Government sponsored research — emphasis is laid on meticulous planning of the work. Estimates of expenditure are often demanded before a new project is approved. On the other hand some scientists — and not only academic dons — recommend a philosophical approach. One of the favourite formulae runs as follows: A problem is recognised and a purpose stated. A literature search is carried out to collect pertinent information. A working hypothesis is formed. Deductions from the hypothesis are drawn. The deductions are tested by experiments.

These are certainly sound principles but the tortuous and fumbling way by which scientists have often arrived at seemingly obvious conclusions suggests that science is not as simple as that. The story of the rare gases may illustrate the point. Towards the end of the 18th century Cavendish reported that a residual constituent of air "stood its ground" against all attempts to combine it with oxygen. A century later an American chemist. Hillebrand, had a mixture of argon and helium in his hands. Adequate means of their detection were at his disposal, yet he failed to recognise these gases as new elements. Then during some 60 years after the discovery of these and other rare gases by Rayleigh and Ramsay they were regarded as chemically inert and their inertness attributed to the completed octet of outer shell electrons became one of the main features of the modern theory of atomic structure.

However, a few years ago it was found that at least some of them do combine with other elements and that the formation of such compounds is remarkably easy. What were the reasons for the delay in discovering rare gases and assessing correctly their chemical nature? Did the scientists concerned not follow the principles outlined above? If they did, maybe there was lack of intuition, creative imagination, critical ability or drive; or maybe too much reliance was placed on theory and too little on experiment. This list of aids to the scientific method is by no means exhaustive; in fact, each instance of breaking a new ground may require some special approach. One can almost risk the view that if there is such a thing as a revelational scientific method no one has yet been able to reveal it