There is some interesting lack of precision, to the point of “error” on the way some concepts are dealt with by human language.
Take, for instance, the concept of drug half-life, i.e. the time that it takes for the concentration of a drug to drop to half (drug concentrations in the blood are normally modeled through exponential decay), it is conceived as a property of the drug - people talk about drug D has an half-life of H hours - but it is really a property of both drugs and individuals (actually is much more complicated than that, we could repeat the argument).
And no, this has not only to do with statistical deviations that are acceptably approached by the drug only.
As example, there is a study about the pharmacokinetic properties of Sulfadoxine-Pyrimethamine (a widely used cheap antimalarial). In this study, there is a big deviation for half-life (and other parameters) for the children between 2 and 5 years. The study concludes that “dose recommendations need revision” for that group. To put in another way, half-life (and other parameters) is not (only) a function of the drug.
Now, I am not suggesting that the concept of half-life tied just to the drug should be thrown away. I am just speculating why it is framed as a function of the drug only, as clearly that is not the case.
First there is probably historical inertia: The concept was first framed that way at a time that it seemed that half-life was only dependent on the drug and it stuck by “memetic” inertia.
But, much more importantly, it is still there because, it is both less expensive (it is easy to express half-life as a function of just the drug, than other parameters which might be still crucial in some situations) and still meaningful enough in many contexts (for instance, expressed as a function of drug it is still useful to compare the half-life of Artemether - short - against Sulfadoxine - long - for many kinds of reasonings). Even when the most economical concept entails some errors it might still be practical. The problem only arises when its simplicity has bad consequences (in this case, having wrong drug doses)… but, in certain contexts, it might be a problem, a serious problem (See my previous text about the notions of resistance, tolerance and sensitiveness for an example).
It all depends of the discourse context, but one should be careful.
As an anecdotal example if you are seriously ill and a doctor prescribes you a pill, do you prefer to hear “this will cure you” or “this will drop the parasite load at a rate of 1 order of magnitude per hour starting 3 (90% CI of 2.5 - 3.5) hours after intake. Parasite load is expected to drop to 0 in 10 hours”?
The problem arises when the cognitive bias of the simplicity of “this will cure you” gets into more rigorous contexts.
This has implications on the computational modeling of concepts. The tradition in computer science it to “dig down” to the “real meaning” of concepts. In that sense simpler explanations are deemed “wrong” (and should be rewritten in terms of “correct” conceptualizations). Maybe a different strategy is needed, one that takes some linguistic and cognitive economy to computational systems (while still maintaining rigorous and precise reasoning and conceptualization when that is needed - like human languages can do).
I am going to stop here, but I think that one of the problems that impairs mathematical modeling is the application of the “certainty of numbers and formulas” to non-rigorous concepts. Then you have the worst of both worlds: an authoritarian argument (mathematics is a foundation for authority. “The numbers prove it”) based on modeling vague, imprecise and wrong concepts. But that is a topic for a another post.
Please share your thoughts
Filed in: bioinformatics, cognition, malaria, science
