W. I. B. Beveridge

The Art of Scientific Investigation




These are the summaries, made by the author, of the various chapters composing The Art of Scientific Investigation. This booklet is one of the most concise and widely circulated text on the art of problem finding and problem solving in the general area of the sciences.




“The lame in the path outstrip the swift who wander from it.” — Francis Bacon (1561-1626)

One of the research worker's duties is to follow the scientific literature, but reading needs to be done with a critical, reflective attitude of mind if originality and freshness of outlook are not to be lost. Merely to accumulate information as a sort of capital investment is not sufficient. Scientists tend to work best on problems of their own choice but it is advisable for the beginner to start on a problem which is not too difficult and on which he can get expert guidance.
The following is a common sequence in an investigation on a medical or biological problem:

  1. The relevant literature is critically reviewed.
  2. A thorough collection of field data or equivalent observational enquiry is conducted, and is supplemented if necessary by laboratory examination of specimens.
  3. The information obtained is marshalled and correlated and the problem is defined and broken down into specific questions.
  4. Intelligent guesses are made to answer the questions, as many hypotheses as possible being considered.
  5. Experiments are devised to test first the likeliest hypotheses bearing on the most crucial questions.



“The experiment serves two purposes, often independent one from the other: it allows the observation of new facts, hitherto either unsuspected, or not yet well defined; and it determines whether a working hypothesis fits the world of observable facts.” — René J. Dubos (1901-1982)

The basis of most biological experimentation is the controlled experiment, in which groups, to which individuals are assigned at random, are comparable in all respects except the treatment under investigation, allowance being made for the inherent variability of biological material. Two useful principles are to test the whole before the part, and to eliminate various possibilities systematically. In the execution of an experiment close attention to detail, careful note-taking and objectivity in the reading of results are important.
Biometrics is concerned with the planning of experiments as well as the interpretation of results. A basic concept in biometrics is that there is an infinitely large, hypothetical population of which the experimental group or data are a random sample. The difficulty presented by the inherent variability of biological material is circumvented by estimating the variability and taking it into account when assessing the results. 
Experimentation, like other measures employed in research, is not infallible. Inability to demonstrate a supposition experimentally does not prove that it is incorrect.



“Chance favours only those who know how to court her.” — Charles Nicolle (1866-1936)

New knowledge very often has its origin in some quite unexpected observation or chance occurrence arising during an investigation. The importance of this factor in discovery should be fully appreciated and research workers ought deliberately to exploit it. Opportunities come more frequently to active bench workers and people who dabble in novel procedures. Interpreting the clue and realising its possible significance requires knowledge without fixed ideas, imagination, scientific taste, and a habit of contemplating all unexplained observations.



“In science the primary duty of ideas is to be useful and interesting even more than to be 'true'.” — Wilfred Trotter (1872-1939)

The hypothesis is the principal intellectual instrument in research. Its function is to indicate new experiments and observations and it therefore sometimes leads to discoveries even when not correct itself.
We must resist the temptation to become too attached to our hypothesis, and strive to judge it objectively and modify or discard it as soon as contrary evidence is brought to light. Vigilance is needed to prevent our observations and interpretations being biased in favour of the hypothesis. Suppositions can be used without being believed.



“With accurate experiment and observation to work upon, imagination becomes the architect of physical theory.” — John Tyndall (1820-1893)

Productive thinking is started off by awareness of a difficulty. A suggested solution springs into the mind and is accepted or rejected. New combinations in our thoughts arise from rational associations, or from fancy or perhaps chance circumstances. The fertile mind tries a large number and variety of combinations.
The scientific thinker becomes accustomed to withholding judgment and remaining in doubt when the evidence is insufficient. Imagination only rarely leads one to a correct answer, and most of our ideas have to be discarded. Research workers ought not to be afraid of making mistakes provided they correct them in good time.
Curiosity atrophies after childhood unless it is transferred to an intellectual plane. The research worker is usually a person whose curiosity is turned toward seeking explanations for phenomena that are not understood. 
Discussion is often helpful to productive thinking and informal daily discussion groups in research institutes are valuable.
Once we have contemplated a set of data, the mind tends to follow the same line of thought each time and therefore unprofitable lines of thought tend to be repeated. There are two aids to freeing our thought from this conditioning; to abandon the problem temporarily and to discuss it with another person, preferably someone not familiar with our work.



“The really valuable factor is intuition.” — Albert Einstein (1879-1955)

Intuition is used here to mean a clarifying idea that springs suddenly into the mind. It by no means always proves to be correct. 
The conditions most conducive to intuitions are as follows:

  1. The mind must first be prepared by prolonged conscious puzzling over the problem.
  2. Competing interests or worries are inimical to intuitions.
  3. Most people require freedom from interruptions and distractions.
  4. Intuitions often make their appearance when the problem is not being worked on.
  5. Positive stimuli are provided by intellectual contacts with other minds such as in discussion, critical reading or writing.
  6. Intuitions often disappear from the mind irretrievably as quickly as they come, so should be written down.
  7. Unfavourable influences include, in addition to interruptions, worry and competing interests, also mental or physical fatigue, too constant working on a problem, petty irritations and distracting types of noises.

Often in research our thoughts and actions have to be guided by personal judgment based on scientific taste.



“Discovery should come as an adventure rather than as the result of a logical process of thought. Sharp, prolonged thinking is necessary that we may keep on the chosen road, but it does not necessarily lead to discovery.” — Theobald Smith (1859-1934)

The origin of discoveries is beyond the reach of reason.
The role of reason in research is not hitting on discoveries — either factual or theoretical — but verifying, interpreting and developing them and building a general theoretical scheme. Most biological " facts " and theories are only true under certain conditions and our knowledge is so incomplete that at best we can only reason on probabilities and possibilities.



“Knowledge comes from noticing resemblances and recurrences in the events that happen around us.”  — Wilfred Trotter (1872-1939)

Accurate observation of complex situations is extremely difficult, and observers usually make many errors of which they are not conscious. Effective observation involves noticing something and giving it significance by relating it to something else noticed or already known; thus it contains both an element of sense-perception and a mental element.
It is impossible to observe everything, and so the observer has to give most of his attention to a selected field, but he should at the same time try to watch out for other things, especially anything odd.



“Error is all around us and creeps in at the least opportunity. Every method is imperfect.” — Charles Nicolle (1866-1936)

The mental resistance to new ideas is partly due to the fact that they have to displace established ideas. New facts are not usually accepted unless they can be correlated with the existing body of knowledge; it is often not sufficient that they can be demonstrated on independent evidence. Therefore premature discoveries are usually neglected and lost. An unreasoning, instinctive mental resistance to novelty is the real basis of excessive scepticism and conservatism. 
Persecution of great discoverers was due partly to mental resistance to new ideas and partly to the disturbance caused to entrenched authority and vested interests, intellectual and material. Sometimes lack of diplomacy on the part of the discoverer has aggravated matters. Opposition must have killed at birth many discoveries. Obscurantism and authoritarianism are not yet dead. 
Included among the many possible sources of fallacy are post hoc, ergo propter hoc, comparing groups separated by time, assuming that when two factors are correlated the relationship is necessarily one of cause and effect, and generalising from observations on samples that are not representative.



“Work, Finish, Publish.” — Michael Faraday (1791-1867)

Tactics are best worked out by the worker engaged on the problem. He should also have a say in planning strategy, but here he can often be assisted by a research director or by a technical committee which includes scientists familiar with the particular field of work. The main function of committees is planning matters of policy. Research can be planned but discovery cannot. 
When discoveries are transferred to another field of science they are often instrumental in uncovering still further knowledge. I have given some hints on how best to go about the various activities that constitute research, but explicit rules cannot be laid down because research is an art. 
The general strategy of research is to work with some clear object in view but nevertheless to keep alert for and seize any unexpected opportunities.



“It is not the talents we possess so much as the use we  make of them that counts in the progress of the world.” — Thorburn Brailsford Robertson (1884-1930)

Curiosity and love of science are the most important mental requirements for research. Perhaps the main incentive is the desire to win the esteem of one's associates, and the chief reward is the thrill of discovery, which is widely acclaimed as one of the greatest pleasures life has to offer.
Scientists may be divided broadly into two types according to their method of thinking. At one extreme is the speculative worker whose method is to try to arrive at the solution by use of imagination and intuition and then test his hypothesis by experiment or observation. The other extreme is the systematic worker who progresses slowly by carefully reasoned stages and who collects most of the data before arriving at the solution. 
Research work commonly progresses in spurts. It is during the “high spots” that it is almost essential for the scientist to devote all possible energy and time to the work. Continual frustrations may produce a mild form of neurosis. Precautions against this include working on more than one problem at a time or having some other part-time occupation. A change of mental environment usually provides a great mental stimulus, and sometimes a change of subject does too. 

There is real gratification to be had from the pursuit of science, for its ideals can give purpose to life.



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