# Name for a logical fallacy: confusing measures in argumentation

I have encountered a line of reasoning in my research which seems to be fallacious.

An example is if you wanted to know something about the general health of an individual, you could measure many different aspects of the individual. You might measure the individual's blood pressure, or you might count the number of cigarettes they smoke each week. Although both of these quantities tell you something about the general health of the individual, and the quantities themselves might be related in complex ways, an individual's blood pressure is not the same thing as the number of cigarettes they smoke each day.

More technically, in ecology, the concepts of both niche and resource selection function (RSF) tell us something about what conditions and resources are important to a species. However, the niche is a geometric object (i.e. think of a polygon in two dimensions), while a resource selection function describes behavior and is an index (single number, scalar) that describes the proportion of used resources relative to the proportion of available resources. Both tell us something about how a species uses resources, but estimating an RSF is not the same as estimating a niche, and vise versa.

If one has an argument and the premises confuse the nature of measures, would this be a logical fallacy, and if so is there a name for it? Please provide sources.

• – Mauro ALLEGRANZA Oct 26 '20 at 15:47
• This is called conflation:"the practice of treating two distinct concepts as if they were one, which produces errors or misunderstandings". – Conifold Oct 26 '20 at 21:21
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• I think Conifold is right that this is an example of conflation, but I was hoping there was a name for this specific form. – Ben Carlson Oct 28 '20 at 21:02

As Conifold has pointed out in the comments, if two numbers are referenced in such a way that they confuse underlying concepts, then a conflation occurs. If those numbers are conceptually very closely related, but the meaning is such that the subtle distinction between them is missed, it may be an equivocation. Lastly, if numbers are used in such a way they poorly represent the central measure of a population, they may be a hasty generalization of some sort. Informal fallacies are highly context-dependent.

Natural Language is complicated and often we use synonyms, paraphrase for simplicity, or draw subtle distinctions with the connotation. In short, polysemy inheres to natural language like white to processed rice. This tends to cause problems in informal logic, where the truth values of one's propositions are highly sensitive to subtle differences in semantics. In fact, two numbers or measures can be conflated in many ways, not only by their essence, but by the mathematical relations they seek to fulfill, and this is a topic usually covered in measurement theory or specifically within a mathematical field such as statistics which has more specific fallacies such as sampling bias.

Per WP:

Conflation is the merging of two or more sets of information, texts, ideas, opinions, etc., into one, often in error... In logic, it is the practice of treating two distinct concepts as if they were one (emphasis mine), which produces errors or misunderstandings as a fusion of distinct subjects tends to obscure analysis of relationships which are emphasized by contrasts.8 However, if the distinctions between the two concepts appear to be superficial, intentional conflation may be desirable for the sake of conciseness and recall.

So, if one (ab)uses logic and arrives at a conclusion where two unrelated concepts are at play both with the special measure, it is conflation. That's different from equivocation. Again, WP:

In logic, equivocation ('calling two different things by the same name') is an informal fallacy resulting from the use of a particular word/expression in multiple senses within an argument.1

A good example of that might be the use of two numbers both of which are averages. As you probably know, there are many measures of central tendency.

Lastly, if the wrong numbers are used specifically within the context of making inferences about populations, it's possible those numbers can be abused in hasty generalization. Let's say someone invokes one measure in the context of describing a sample, but that number is irrelevant to drawing an inference about the population for whatever reason, then any conclusion reached would be unwarranted.

One should also bear in mind that from a logic perspective, the misuse and confusion of numbers cannot only affect the validity or strength of the argument, but the soundness and cogency of propositions depending on the effect on their truth-values (binary, multivalued, or infinite). That is to say, that a bad predication can occur in the proposition itself making the premise unsound or weak leading to an unsound or uncogent conclusion.

Appendix:

This is called conflation:"the practice of treating two distinct concepts as if they were one, which produces errors or misunderstandings". – Conifold

• Thank you for this detailed answer. I think you are right that the scenario is a form of conflation. However, since there can be many underlying reasons for conflation, I was hoping there was a name for the specific form of conflation that I described above. Your example of different measurements of central tendency is a good one (continued in next comment). – Ben Carlson Oct 28 '20 at 20:51
• (continued from above) I think you might also describe the scenario in terms of set notation: if A is a proper subset of C, and if B is a proper subset of C, this does not mean that A = B. I was hoping there was a formal name for this type of logical error, but perhaps it just falls under the more general error of conflation. – Ben Carlson Oct 28 '20 at 20:51
• Another example might be a modified version of the "Map-territory relation" en.wikipedia.org/wiki/Map%E2%80%93territory_relation. Say I had a map that describes a territory, and a text description of the territory. Both describe the territory but this does not mean that the map and the text description are the same thing. They have overlapping information but also some unique information and the representation of that information is different. – Ben Carlson Oct 28 '20 at 20:57
• @BenCarlson After a quick scan of your follow-up, the fallacy of the undistributed middle comes to mind which is close. I love Korzybski's quotation (with the same measure of my disdain for Platonic forms), so let me reread your question and clarification and it give it some thought. – J D Oct 28 '20 at 21:02