The Method of Multiple Working Hypotheses: Is It A Chimera?



Thomas Crowder Chamberlain (1897) begins his classic essay “The Method of Multiple Working Hypotheses” with the words, “There are two fundamental modes of study. The one is an attempt to follow by close imitation the processes of previous thinkers and to acquire the results of their investigations by memorizing. It is a study of a merely secondary, imitative, or acquisitive nature. In the other mode the effort is to think independently, or at least individually. It is primary or creative study. The endeavor is to discover new truth or to make a new combination of truth or at least to develop by one’s own effort an individualized assemblage of truth. The endeavor is to think for one’s self, whether the thinking lies wholly in the fields of previous thought or not. “


Chamberlain continues by describing what he considers to be the three prominent phases of mental procedure in the history of intellectual evolution thus far. According to Chamberlain these three phases are the method of the ruling theory, the method of the working hypothesis, and the method of multiple working hypotheses (MWH). The working hypothesis, according to Chamberlain, “differs from the ruling theory in that it is used as a means of gathering facts rather than as a proposition to be established. It has for its chief function the suggestion and guidance of lines of inquiry; the inquiry being made, not for the sake of the hypothesis, but for the sake of the facts and their elucidation.”


While Chamberlain considers the method of the working hypothesis far superior to the method of the ruling theory, he notes the ease “with which the hypothesis becomes a controlling idea.” To avoid this danger Chamberlain urges MWH use, which “differs from the simple working hypothesis method in that it distributes the effort and divides the affections.”  Chamberlain proceeds, “In developing the multiple hypotheses, the effort is to bring up into view every rational explanation of the phenomenon in hand and to develop every tenable hypothesis relative to its nature, cause or origin, and to give to all of these as impartially as possible a working form and a due place in the investigation. The investigator thus becomes the parent of a family of hypotheses; and by his parental relations to all is morally forbidden to fasten his affections unduly upon any one.”


J.G. Johnson claims MWH is a chimera and should be laid to rest


Twenty-three years ago J.G. Johnson (1990) published an essay titled “Method of Multiple Working Hypotheses: A chimera” in which he claimed, after commenting on repeated support many scientists give to T.C. Chamberlain’s MWH, that “few scientists (if any) actually use the Method.” Johnson went on to suggest, “The reason for this paradox is uncritical acceptance by the Method’s supporters. Either they have not read Chamberlain’s paper without examining its logic or they have not read it at all, but suppose that the Method is what its title evokes in their minds. A hard look at what Chamberlain’s Method really is suggests that it be laid, at last to rest.”


Why did Johnson believe the method of MWH should be laid to rest? He states, “Chamberlain is not only calling on scientists to think of several answers to a question, he is asking them to test every possible answer. It is an unrealistic expectation. Imagine the time and effort wasted if every lab set up simultaneous experiments to test all of the evident explanations of a phenomenon. No science is done that way. Possible answers are weighed often very quickly, and one is brought forth as a hypothesis to be tested. If it meets the test it is afforded predictive value to explain other situations, which is a further test that may lead to modifications…. It is the method of the working hypothesis.”


Johnson continues by arguing, “It is pathetic to imagine the scientist mind-juggling several hypotheses at one time as a way of avoiding his own weak-willed tendencies to follow only his favorite explanation. …Chamberlain claims that MWH, by its very nature, promotes thoroughness. Being thorough indisputably has value, but, when it requires a scientist develop (test) all ideas without favoring one, that is carrying thoroughness to the point of absurdity.”


Johnson further argues, “For me, bringing all possible hypotheses into mind is the first order of things, not the result of a methodology such as MWH, which involves ‘serious inquiry’ and ‘the investigation of all possibilities’.  Chamberlain’s suggestions seem a de facto attempt to validate an unrealistic methodology by attributing to it the most ordinary of good practices.” Johnson then adds, “There is in the real world, a way by which explanations of phenomena are achieved by consideration of all available information, and that is insight, but insight is not a method. It cannot ordinarily be chosen as a means to an end, nor can fortuitous discovery. But neither is simply thinking about all possible explanations a method to arrive at answers in science. When MWH is evaluated critically, its unreality as a method cannot be avoided.”


Before concluding his essay Johnson reiterates “that the working hypothesis is a realistic and ordinary approach, requiring only that scientists be able to change their minds as new information appears. A thousand data bits may lead to a satisfying hypothesis, but the next data bit may require a reassembly of all 1001. A good scientist can do that.” Johnson then concludes with the words, “The goal of MWH is perhaps accomplished these days by the totality of minds and motivations in a diverse community, acting through time, but not in the mind of any single individual. The method of Multiple Working Hypotheses, as espoused by Chamberlain, is only a chimera; it deserves to be laid to rest.”


MWH strengths and drawbacks Johnson does not address


Johnson did not address Chamberlain’s claim that “When faithfully followed for a sufficient time, it [MWH] develops a mode of thought of its own kind which may be designated the habit of parallel thought, or of complex thought. It is contra-distinguished from the linear order of thought which is necessarily cultivated in language and mathematics because their modes are linear and successive. The procedure is complex and largely simultaneously complex. The mind appears to become possessed of the power of simultaneous vision from different points of view. The power of viewing phenomenon analytically and synthetically at the same time appears to be gained. It is not altogether unlike the intellectual procedure in the study of a landscape. From every quarter of the broad area of the landscape there come into the mind myriads of lines of potential intelligence which are received and coordinated simultaneously producing a complex impression which is recorded and studied directly in its complexity.”


Nor does Johnson appear to recognize that Chamberlain also said, “No good thing is without its drawbacks. It is obvious upon studious consideration that a complex or parallel method of thought cannot be rendered into verbal expression directly and immediately as it takes place. We cannot put into words more than a single line of thought at the same time, and even in that the order of expression must be conformed to the idiosyncrasies of the language. …The impossibility of expressing the mental operation in words leads to their disuse in the silent processes of thought and hence words and thoughts lose that close association which they are accustomed to maintain with those whose silent as well as spoken thoughts predominantly run in linear verbal courses. There is therefore a certain predisposition on the part of the practitioner of this method to taciturnity. The remedy obviously lies in coordinate literary work.”


Why Johnson did not mention mental processes developed by repeated use of MWH or the difficulty of expressing complex thought in words is difficult to say. Perhaps Johnson, who during his relatively short lifetime was a paleontologist, had been trained to think linearly and never developed the habit of parallel and complex thought. If so, Johnson may not have considered complex and parallel thought a useful research skill. It is also possible Johnson, when he says “For me, bringing all possible hypotheses into mind is the first order of things,” is describing a complex and parallel thought process which he believed every scientist uses. Still another possibility is Johnson did not read Chamberlain’s complete essay. Whatever the reason, Johnson makes no mention of the mental processes Chamberlain claims repeated use of MWH develop.


Use of MWH in normal science


Scientists working entirely within the context of their discipline paradigm are conducting what Thomas Kuhn calls normal science. A paradigm according to Kuhn is a framework of ideas based upon one or more past scientific achievements that some scientific community acknowledges for a time as supplying the foundation for its further practice. According to Kuhn normal science is also “an attempt to force nature into the preformed and relatively inflexible box that the paradigm supplies.” In normal science, according to Kuhn, “there is no effort to discover anomalous evidence, new types of phenomena, or to invent new theory, and there is little tolerance for scientists who try to do so.” In other words, in normal science an existing paradigm skeleton is fleshed out.


Scientists doing normal science do not seek novelties and as a result are usually guided by their discipline paradigm when asking research questions and developing hypotheses. Often their paradigms quickly suggest hypotheses to test, just as Johnson describes. For this reason many scientists doing normal science may see little need to spend time and effort developing and testing multiple hypotheses. However, there are numerous situations in normal science where MWH can and should be applied.


The creation of new knowledge in normal science is like adding rooms to an already constructed building framework. Regardless of where in the framework a room is, the added room must be contained within the building and must also fit into the overall building design. However, within those constraints there are many different ways in which the room can be added. Paradigms in normal science are the pre-existing frameworks, which guide scientists as research questions are asked and as evidence is observed and analyzed. And, as in the building analogy, there are different ways by which a paradigm can be fleshed out. MWH can and should be used by scientists doing normal science to discover best ways to flesh out their discipline paradigms.


An even more important MWH application in normal science occurs in the situation Johnson describes when he says, “A thousand data bits may lead to a satisfying hypothesis, but the next data bit may require a reassembly of all 1001.” While Johnson says a good scientist can do the reassembly, what Johnson does not say is the reassembly should be done by the development and testing of alternate working hypotheses, in other words by application of MWH. However, scientists who have little or no experience applying MWH may simply set aside the odd data bit as anomalous evidence and continue to use their satisfying hypothesis to flesh out their discipline paradigm, just as though the anomalous data bit did not exist.


Using the method of MWH to explain anomalous evidence


According to Kuhn “normal science does not aim at novelties of fact or theory and, when successful finds none, new and unsuspected phenomena are, however, repeatedly uncovered by scientific research.” Discovery for Kuhn begins with awareness of anomaly or recognition that nature has violated the paradigm-induced expectations that govern normal science. Kuhn further argues that normal science makes anomalies appear, because the anomalies appear only against the background provided by the paradigm. Kuhn continues by saying that recognition and acknowledgment of anomalies cause crises that result in the emergence of new paradigms. To Kuhn all scientific crises begin with a blurring of a paradigm and a loosening of the rules of normal science. Kuhn then argues the crises are resolved in one of three ways. Sometimes normal science may prove capable of handling the problem and normal science returns. Other times, the problem persists and is recognized and labeled, but is set aside for a future time when better research tools are available. Or, finally the “crisis may end with the emergence of a new candidate for paradigm and with an ensuing battle over its acceptance.”


Scientists doing normal science do encounter anomalous evidence, although the anomalous evidence may not always be recognized. Many scientists upon encountering unexplainable evidence simply report seeing the evidence and make no further effort to understand what the evidence might mean, which is the equivalent of labeling the evidence and then setting the evidence aside for future work. At some point, either immediately after the anomalous evidence is first encountered, or after the anomalous evidence has sat on the sidelines for many years, some scientist will attempt to explain the evidence. The challenge such a scientist faces is laid out by the problem Johnson describes. If a satisfactory hypothesis explains 1000 data bits and does not explain one additional data bit, then an equally satisfactory explanation that explains all 1001 data bits needs to be found. To find that equally satisfactory hypothesis the scientist needs to develop a family of new hypotheses able to explain all 1001 data bits.


Usually scientists trying to explain anomalous evidence use a MWH modified form. Recognizing the evidence cannot be explained by what were previously satisfactory hypotheses the scientist must develop completely new hypotheses to explain the evidence. In such situations the scientist frequently has no preferred explanation and begins by developing and testing modifications of the previously satisfactory hypothesis. If all conceivable modifications of the previously satisfactory hypothesis fail the process then usually involves developing and testing every conceivable hypothesis the prevailing discipline paradigm suggests before moving on to the next step, which involves a blurring of the paradigm and normal science rules. The process of developing and testing these families of multiple working hypotheses often leads the scientist to additional anomalous evidence, which in turn almost always leads to still more anomalous evidence.


Scientists blur paradigm and normal science rules very reluctantly, and only after becoming convinced no other course of action satisfactorily explains their evidence. A good scientist will recognize the paradigm and normal science rules are being blurred, but will still be bound by fundamental rules of science that, regardless of paradigm, apply to all scientific work. These rules of science are as follows: First, all interpretations must be based on observable evidence that actually exists. Second, interpretations must be based on all of the observable evidence or at least a representative sample of the observable evidence. Third, all interpretations must be based on common sense logic. Fourth, all interpretations must be consistent with all of the evidence and with each other. Fifth, when two or more explanations explain the same evidence, unless there is good reason to believe otherwise, science almost always prefers the simplest explanation. Sixth, all interpretations are subject to future revision and must stand the test of time.


Probably by the time a good scientist begins to blur the discipline paradigm and normal science rules MWH will have been applied repeatedly and dozens of alternate working hypotheses will have been developed and tested, none of which involved any blurring of the paradigm or normal science rules. When blurring paradigm and normal science rules such a scientist will once again need to employ MWH, this time by following the above described basic rules of science as completely new families of hypotheses are developed and tested. In such situations the scientist may have to spend many years developing and testing multiple families of hypotheses before finding a hypothesis that both explains a mass of anomalous evidence and also the evidence the discipline paradigm and normal science had previously explained. The successful explanation, if it is found, will allow the scientist’s discipline to recognize at long last the anomalous evidence, and will also trigger what Kuhn calls a scientific revolution, which will define a new discipline paradigm and open up new and expanded discipline research opportunities. However, prior to every scientific revolution some scientist must repeatedly apply MWH.


Discussion and conclusions


Johnson is certainly correct when he says, “the goal of MWH is perhaps accomplished these days by the totality of minds and motivations in a diverse scientific community,” although he makes a serious error when he states MWH cannot be accomplished in “the mind of any single individual.” At least some scientists use MWH, whether consciously or not, when comparing and contrasting hypotheses to find the best hypothesis to explain normal science phenomena. At least some scientists use MWH, again whether consciously or not, when they attempt to explain what to them is unexplainable anomalous evidence. And, any scientist forced by large masses of unexplainable anomalous evidence to blur discipline paradigm and normal science rules almost certainly has to use MWH as alternate paradigms are developed and tested.


Do all scientists use MWH? Johnson suggests most scientists do not. He may be correct. If so, that means most scientists do not address whatever anomalous evidence they encounter, and as a result do not reassemble the data bits that Johnson says a good scientist can do. In many scientific disciplines there are no short-term penalties if scientists neglect anomalous evidence and pursue erroneous hypotheses, especially if their colleagues are also neglecting anomalous evidence and pursuing erroneous hypotheses. The penalties may not show up until many years in the future, when a completely different group of scientists finally applies MWH and does the reassembly of data bits described by Johnson. Scientists who encounter anomalous evidence and who do not apply MWH in an effort to incorporate that evidence into their hypotheses are leading their disciplines down very slippery and dangerous paths, but may never know their errors. Good science needs MWH, if only to explain anomalous evidence, and will cease to exist if MWH is ever laid to rest.


References cited


Chamberlain, T.C., The method of Multiple Working Hypotheses; Journal of Geology, v 5, p. 837-848.


Johnson, J.G., 1990, Method of Multiple Working Hypotheses: A chimera; Geology, v.18, p. 44-45.


Kuhn, T. S., The Structure of Scientific Revolutions (second edition, enlarged); The University of Chicago Press. 210 pages.



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