Can ISM cope with differences in terminology?

    The "Introduction to the ISM Framework" states that "there is no consistent terminology; instead, there are important terms...with many conflicting meanings, and meanings known by many names."  This leads to the question, "Can ISM describe the views of a person who uses different terms than those in ISM, or who defines the ISM terms differently?"
    There are several possible responses to this challenging question.  One approach attempts to solve conflicts by a simple substitution of one term for another.  But a more sophisticated approach is needed for the really tough inconsistencies; for these conflicts a "solution" seems impossible, but there may be ways to minimize the confusion.  And in any case, difficulties arising from choices about terms are not unique to ISM; because of the widespread inconsistency in terminology, every description of science faces a similar challenge.
    Substitution is an easy way to cope with some differences.  For example, the same process of logic is known by two common names: retroduction and abduction. [1]  There are good reasons to use 'retroduction', [2] but if someone wants to replace this term with 'abduction' it would cause no significant change in ISM.  Another potential candidate for substitution is 'experimental system'; in ISM this is defined as "everything involved in an experiment" for a reason, [3] but sometimes scientists define a system as only "what is being studied," with "what is done to it, and the instruments of observation" being external to the system.  In this case, 'experimental system' could be replaced by another term, such as 'experimental setup' or 'a system and its experimental context'; this substitution would not alter the hypothetico-deductive logic used in the ISM framework.  Or someone might want to replace theory 'invention' with 'development' or 'generation'.

    But for three ISM terms -- model, hypothesis, and theory -- the situation is more complex.  Part of the difficulty is inconsistent terminology;  these terms and others (such as principle, law, concept, or conjecture) are often used with similar or overlapping meanings, or with contrasting meanings that differ from one definer-of-terms to another.  The overall use of these terms lacks both consistency and precision.
    The term 'model' is used in many ways, so no matter how this term is used there will be conflicts with other definitions.  Often it seems to be a synonym for a theory or sub-theory, or for a certain type of theory.  Or it can refer to an exact application or (more commonly) a simplified application of a theory for a certain type of system, as when Giere (1988, 1994) defines a theory in terms of "families of models."  For example, the theory of Newtonian Mechanics includes many models and families of models, such as gravity-driven motion on an inclined plane with no friction, or with friction, or with friction plus air resistance.  Giere thus uses the term 'model' in two ways that are different yet compatible:  each of the models (that together comprise the theory) can be useful when constructing a model (as this term is used in ISM's hypothetico-deductive box) for certain experimental systems.  For example, an 'inclined plane' family of models is a useful shortcut when applying Newton's theory for a specific system that is a member of the corresponding family of systems, while a 'pendulum' family of models is useful for theory application within another family of systems.  By analogy with the distinction between 'domain-theories' and 'system-theories' in Section 2.05, there can be 'domain-models' (such as the family of inclined plane models that occurs when Newton's theory is applied, in various ways, within the domain of inclined plane systems) and 'system-models' (resulting from the application of Newton's theory, in a certain way, to specific inclined plane systems).  And, analogous to the influence of a domain-theory on system-theories, a general domain-model (about systems in a domain) will influence the construction
    'Hypothesis' has an even wider variety of conflicting meanings.  Consistent with Giere (1991), ISM defines a hypothesis as a claim that a theory-based model is similar to a real-world system "in indicated respects and to an implied degree of accuracy. (Giere, 1991, p. 27)"  Gibbs & Lawson (1992) define it as "a single proposition intended as a possible explanation...for a specific effect (p. 143)" in contrast to "a theory...intended to explain a broader class of phenomena and consisting of multiple hypotheses and/or general postulates that, taken together, constitute the explanation (p. 149)";  but the authors report with dismay that "a number of textbooks give examples of hypotheses that clearly are predictions, not hypotheses (p. 147)," and that most authors "define theories as hypotheses that have been supported over a long period of time (p. 147)" even though according to the authors' own definitions "the evidence may or may not support a theory (p. 148)" -- for example, the Ptolemaic Theory of earth-centered planetary orbits is still considered to be a theory even though it now has low status.  Darden (1991, p. 17) describes two meanings for theory -- it can be "[a claim that is] hypothetical, not yet proven" or "a well-supported, general, explanatory claim" -- and chooses the latter definition to use in her analysis; and she defines a hypothesis as "a proposed alternative to a theoretical component. (p. 18)"  Grinnell (1992) usually uses hypothesis in the same way that ISM uses theory (a word he never uses) -- for example, he says that scientists "imagine hypotheses to explain these regularities...in observed natural events (p. 1)," and in criticizing the model of theory falsification (Popper, 1963), he says that "according to this model, science progresses through selective falsification of competing hypotheses, ... [and] it takes only one negative result to call a hypothesis into question (p. 40)" -- but sometimes this word changes meaning and is a prediction: "[an explicit hypothesis] is the change "
    The chaotic state of terminology is captured in the paragraph above.  In it, hypothesis is defined -- by Giere, Gibbs & Lawson, Darden, and Grinnell, all authors whose work I respect -- as a claim about a model for one system, or an explanation for a type of phenomenon, a sub-theory or theory component, a prediction, a new theory with low status, a newly proposed theory component, and a theory.  What a wild mix!  Generally, however, the difference between hypothesis and theory tends to be defined along two dimensions -- scope and certainty. [4]   When both factors point toward the same choice of a term there is general agreement, which includes myself and ISM, about definitions:  if a proposed explanation has narrow scope and low status, it is a hypothesis;  if it has wide scope and high status, it is a theory.  With mixed criteria (narrow scope and high status, or wide scope and low status) there is less agreement.  Another criterion is age; older explanations tend to be called theories, not hypotheses.  For example, the Ptolemaic Theory remains a theory even though it currently has very low status;  once a theory, always a theory?

    In ISM the distinction between a hypothesis and theory depends only on scope;  age doesn't matter;  and a hypothesis can have either low status or high status, as can a theory.  In ISM (and for Giere) the criterion for scope is clear;  a hypothesis refers to one system, while a theory refers to two or more systems.  By contrast, the other authors define hypothesis more "broadly" or "generally".
    I do not claim that my use of 'hypothesis' and 'theory' is the best possible solution for this "terminology problem."  The principle advantages of my definitions are logical simplicity and internal consistency.  The main disadvantage is that, despite agreement with the use of terms by some philosophers (especially Giere) there is disagreement with other philosophers and with most scientists. 
    There are significant logical advantages, described below, in using the ISM terms.  These advantages carry over to practical concerns.  For example, with one non-ISM definition a low-status theory (hypothesis) may eventually become a theory, but before this occurs the hypothesis occupies the same status as 'theory' does in the current ISM.  This means that everywhere in the ISM diagram where "theory" appears (15 places) it would have to be replaced by "theory or hypothesis";
    A logical disadvantage of this non-ISM definition is that if "hypothesis" appears in the "theory" oval (on the left side of the diagram) rather than in the hypothetico-deductive box, how does 'hypothesis' enter into 'hypothetico-deductive' reasoning when a theory
    A logical advantage of the ISM definition of theory, which avoids the use of status in defining a theory, is that this lessens the rhetorical value of using the term 'theory' to influence critical thinking.  For example, in the quotations cited above Darden describes two ways to define a theory;  in one a theory is "hypothetical, not yet proven" while in the other it is "well-supported," so the same word can be used to imply low status or high status!  I think it is better to evaluate a proposed explanation (i.e., a theory) based on merit rather than terminology.  We can just say "here is a proposed explanation; now we can decide how well supported it seems to be," instead of trying to short-circuit the critical process by saying "it is a theory so it is not proven" or "it is a theory so it is well supported."  Another difficulty in drawing a demarcation line between hypothesis and theory is pointed out by Gibbs & Lawson (1992): "Who decides when an hypothesis becomes a theory?"
    There are many logical and practical reasons to use the definitions I have chosen for ISM;  these reasons have overcome [in my thinking and decision-making] the advantages of using a more commonly used definition.  This is one of the few places where I am aware of ISM being normative by "prescribing" how things should be done in science, by saying "this way is more logical and practical."  This decision was made easier by the fact that no matter which definitions I use in ISM, they will be inconsistent with the many other definitions that are commonly used;  it is impossible to be consistent with inconsistency.

 
    FOOTNOTES

    1. Almost everyone uses these two terms as synonyms, but as usual there is variation.  Ernst McMullin (1992) uses 'abduction' to mean the same thing that 'retroduction' does in ISM, but he uses 'retroduction' to describe a wider-ranging process of thinking that includes "abduction and more."

    2. I decided to use 'retroduction' in ISM, for two reasons.  First, the prefix 'retro' is a reminder that this logic is oriented backward in time, to explain what already has occurred.  Second, if ISM is to be maximally useful for science education, and if part of this usefulness occurs when teachers encourage children to learn a productive form of creative-and-critical thinking, it seems unwise to call this desirable activity 'abduction' -- a term whose primary common meaning is the undesirable activity of kidnapping.

    3. Observations are produced by an experiment that involves everything in the experimental system.  And to make predictions a model must consider everything, including the instruments of observation.

    4. But if a hypothesis is defined as a theory-component (as it is by Gibbs & Lawson, and by Darden), this is not necessarily the same as having narrow scope (which is also used by these authors to define a hypothesis), because a component can have wide scope.