Everything I’ve encountered on “systems theory” suggests to me that there is no such thing. The writings generally consist of a large quantity of words about the definitions of other words, but no mathematics and no predictions that were not already there before pulling it into the ambit of “systems”.
I consider control theory to be a part of systems theory and given that you give a talk on the virtues of control theory I think you value it. Apart from that my thoughts about the space:
If you look at Seth Roberts’s Shagri-La diet it’s based on systems thinking. It gives different answers than the standard nutritional paradgim which thinks that losing weight is about linear effect of eating less and exercising more.
You don’t need any math for understanding the Shangri-La diet but you do need a certain intellectual framework that considers systems to be important.
Mathematical predictions are only one aspect a theory can provide. Systems theory provides phenomenlogical primitives that can prevent you from dismissing the Shangri-La as strange and obviously crazy.
It provides you with a better ontology that allows you to consider new solutions.
Hakob Barseghyan describes in his HPS100 course very well how the notion of a life force being important for biology came after Newton changed the accepted ontology and that people basically thought that there’s matter and that matter interacts via forces with other matter. Our current mainstream ontology of physicalism doens’t consider that a place for a vital force exists.
If we go back to Seth Roberts, Seth considers it a good idea to measure the fitness of a human by measuring the reaction time to short math queries. I don’t think Seth wrote anywhere that he’s measuring a “vital force” by doing so, but if you go back in history you find that people have measured the vital force via reaction tests.
Gunnar Stollberg argues that modern systems biology has a concept like the vital force with self-organisation/autopoiesis.
A reemergence of vitalism could help explain why a student person who writes down their ideal life or writes about an emotional trauma for 4 days afterwards lead to significantly less sickness as Laura King showed in “The Health Benefits of Writing About Life Goals”.
Systems theory puts us in the position were we don’t have to postulate any paranormal chi for a notion like life force to exist. It doesn’t need math for that task.
I consider control theory to be a part of systems theory and given that you give a talk on the virtues of control theory I think you value it.
I certainly value the theory of control systems, and I think everyone should know its basic concepts. But the real thing looks like this (and all of the stuff that that links to). This is quite unlike what I’ve seen under the banner of “systems”, including some of the references in the OP.
To be more positive, I get from some of your examples the idea that “systems thinking” means “not being stupid.” Specifically, not being the sort of stupid that consists of thinking up a theory that is “obviously” true and failing to see whether it is. I don’t have a problem with that sort of “systems theory”.
Gunnar Stollberg argues that modern systems biology has a concept like the vital force with self-organisation/autopoiesis.
But he concludes by admitting that biologists have not taken this up (and briefly, absurdly, considers the hypothesis of a conspiracy to suppress it).
This is where it seems to me to wander off into the fog. Vitalism is an idea with no moving parts. As soon as you have moving parts to explain the phenomena that people pointed to and said “vital force!” as an explanation, the notion of vital force, goes away. Likewise autopoiesis. The observation that organisms maintain certain variables fixed despite disturbing influences is not explained by giving the phenomenon a name. The thing for a scientist to do is to discover the mechanism. For example, where does a mammal’s body sense its core temperature? How is the reference signal generated, and raised in case of fever? And so on. When the whole story is known, we know not merely that it self-regulates, but how.
To be more positive, I get from some of your examples the idea that “systems thinking” means “not being stupid.”
Not being stupid in way where the majority of our society is stupid.
But he concludes by admitting that biologists have not taken this up
Just as the majority of nutrition scientists haven’t taken up Seth Robert’s Shangri-La diet or did research in that direction.
When hearing the discussion of a topic like homeopathy I never see references to the fact that quizing a patient for two hours for the trauma of his life instead of talking with him for 5 minutes has a good chance to have benefitial health effects. It’s well replicated that writing about your trauma’s creates health benefits. That’s because of the paradigm in which our medicine is practiced.
Calling that mysterious variable that get’s raised by writing about trauma “vital force” might not be a good explanation but once you go that step you can ask new research questions. If you allow people to simple call it vital force you allow new questions. Is there a way to measure it? Can we measure the “vital force” a day after the trauma writing and see whether the writing worked at raising the vital force? Can we then use that score to predict days of illness?
The thing for a scientist to do is to discover the mechanism
If you believe that’s the only thing scientists are allowed to do then they won’t be able to do work where predictions can be made but where the underlying mechanism is illusive.
Would you forbid psychologists from talking about IQ and g because they can’t tell you the mechanism in which IQ/g works?
Currently dualism isn’t dead. Psychologists who work on the mind are allowed to use the concept of IQ without providing an mechanism but biologists are not allowed to do something similar with a life force metric.
Just be complete, no I don’t think that there’s a conspiracy that forbids biologists from doing so. It’s just that the paradigm and people being stupid. I think systems theory provides a way out.
Would you forbid psychologists from talking about IQ and g because they can’t tell you the mechanism in which IQ/g works?
It depends what they say about it. There are observable and fairly robust statistical correlations from which g can be constructed, and g can be used to make (rather weak in the individual case) predictions of various sorts. That does not make g a thing. I predict that if we ever find out how the brain works, g will not be a part of that mechanism, just a rough statistical regularity, as it is at present.
Currently dualism isn’t dead. Psychologists who work on the mind are allowed to use the concept of IQ without providing an mechanism but biologists are not allowed to do something similar with a life force metric.
If life force is going to be the same sort of thing as g, it might be useful in medicine, which to a substantial and increasing extent is based on statistical trials with little knowledge of mechanisms. But I don’t see it as useful for research into how things work.
If life force is going to be the same sort of thing as g, it might be useful in medicine, which to a substantial and increasing extent is based on statistical trials with little knowledge of mechanisms. But I don’t see it as useful for research into how things work.
I think that “finding out how things work” should not be the goal of science. The goal should be to develop models that provide reliable and useful predictions.
Newton postulate gravitation as a force without telling his audience how gravity works. The fact that Newton couldn’t explain that slowed down adoption of his model, yet accepting his model brought science a huge step forward. Even on many issues that are about research into how things work.
Theories that provide additional predictive power help science advance even if their proponents can’t explain everything from the ground up.
To get back to system theory. It allows us to say: “Emergence” when we don’t know how something come about and still work with what comes about.
When someone tells you that homeopathy doesn’t work because there are no infinitively small numbers of atoms he has a valid argument. Our ontological framework doesn’t allow the infinitively small numbers of atoms. People who have never heard of systems theory and subfield of it like control theory will have a similar reaction to the Shangri-La diet as to homeopathy. The ontology doens’t allow for it.
System theory then allows for an ontology in which it can happen. That’s valuable. When you go through a specific example you can also think about what the various words of system theory might be when you apply it to the system you study. That provides you with a structure to model the problem even if you don’t have enough data for mathematical modelling.
We have no idea how the set point for blood pressure is that in the human body, but it’s worthwhile to think of blood pressure regulation as a sytem that has a set point even if we don’t know how that is set.
From a medical standpoint we can think differently about the system through looking at it with the lense of system theory.
To get back to the life force, it’s good when we get more free and focus on increasing the predictive power of our models without worrying too much about whether we know at the moment the mechanism behind a certain value.
Sometimes it can even be useful to free our concepts from wanting to explain mechanisms. A term like Shaken Baby syndrome can be quite problematic if you find out that 1% of the cases of babies with “Shaken baby syndrome” weren’t shaken.
The thing for a scientist to do is to discover the mechanism
If you believe that’s the only thing scientists are allowed to do then they won’t be able to do work where predictions can be made but where the underlying mechanism is illusive.
“Discover”, not “have discovered”. Newton’s work was a step; Einstein finding more of a mechanism was a further step.
I think that “finding out how things work” should not be the goal of science. The goal should be to develop models that provide reliable and useful predictions.
It’s difficult to get the latter without the former, if you want to make successful way-out-of-sample predictions. Otherwise, you’re stuck in the morass of trying to find tiny signals and dismissing most of your data as noise.
It’s difficult to get the latter without the former, if you want to make successful way-out-of-sample predictions.
I think you can do a lot of successful predictions with IQ without knowing the mechanism of IQ. I don’t think you build better IQ tests by going into neuroscience but giving the tests to people and seeing how different variables correlate with each other.
Otherwise, you’re stuck in the morass of trying to find tiny signals and dismissing most of your data as noise.
I don’t think that’s true. The present approach of putting compounds through massive screening arrays based on theoretical reasoning that it’s good to hit certain biochemical pathways is very noise-laden and produces a lot of false positives. >90% of drug candidats that get put into trials don’t work out.
I think “system theory” used to be called cybernetics and (in its contemporary form) was basically invented by Norbert Wiener.
This might be splitting hairs, but I would probably call it a “framework” in the sense that it provides a context (e.g. language and concepts) within which more specific “theories” exist. Which theory, for example, would consider the similarities between feedback mechanisms in financial markets and in ecological systems?
Which theory, for example, would consider the similarities between feedback mechanisms in financial markets and in ecological systems?
Dynamic systems. I am not convinced it gains from being associated with a wider “systems theory”.
Of perhaps, like Molière’s bourgeois gentilhomme discovering that he had been speaking prose all his life, the message is that “systems thinking” is what I have always been doing?
Of perhaps, like Molière’s bourgeois gentilhomme discovering that he had been speaking prose all his life, the message is that “systems thinking” is what I have always been doing?
Might be :-) I think cybernetics / system theory basically dissolved into a set of disciplines or theories, much like natural philosophy did a long time ago or, say, geography did fairly recently.
I think of it more like a particular lens from which to view problems, i.e. it is an alternative to reductionism. But, perhaps it’s most useful aspect is that it allows the development of techniques which can be used to simulate complex systems. Ludwig von Bertalanff described the set of theories that together comprise the framework of systems thought in the following passage:
Now we are looking for another basic outlook on the world—the world as organization. Such a conception—if it can be substantiated—would indeed change the basic categories upon which scientific thought rests, and profoundly influence practical attitudes. This trend is marked by the emergence of a bundle of new disciplines such as cybernetics, information theory, general system theory, theories of games, of decisions, of queuing and others; in practical applications, systems analysis, systems engineering, operations research, etc. They are different in basic assumptions, mathematical techniques and aims, and they are often unsatisfactory and sometimes contradictory. They agree, however, in being concerned, in one way or another, with “systems,” “wholes” or “organizations”; and in their totality, they herald a new approach. Quoted from: Systems Theories: Their Origins, Foundations, and Development
If you want to deep dive into complex systems, I found this to be useful.
My impression is that there are a few core ideas which get turned into frameworks by different people every few years because rediscovery + the generative effect are more fun/epiphany inducing than reviewing the entire literature.
WRT predictions: systems theory is about modelling, and modelling is always making implicit predictions about the causal structure of the system. The better ‘systems theory frameworks’ encourage turning these into explicit predictions/tests.
You seem to be tacit assuming that only a quantiative, predictive theory is a theory at all, but as far as general usage goes, the horse has bolted, because we have critical theory, cultural theory and other such handwavey things.
Many things are called theories, but they are not all the same sort of thing. I know little of critical theory or cultural theory, but I have a very slight acquaintance with music theory, so let me say what sort of thing that appears to be to me, and ask if these other “theories”, including systems theory, are a similar sort of thing.
Musical theory is not the same sort of thing as the theory of Newtonian mechanics. It is more like (pre-neo-Darwinian) biological taxonomy (although different in important ways I’ll come to). That is, it is an activity of classifying things into a framework, a structure of concepts. It makes no predictions, other than that these regularities will continue to be observed. Just as in taxonomy: when you come across a creature that you identify as a heron, you can be sure of a lot of things that you will subsequently observe if you follow it around. But there is no biology here: the classification is based purely on the appearance (perhaps including the results of microscopy) and behaviour of the organism, with no deeper knowledge to tell you how the variety of creatures came to be, or the biochemical processes by which they function. And just as in the history of taxonomy various classification schemes have been proposed, so in music theory there are alternatives to the standard stuff found in elementary textbooks (e.g. Schenkerian theory, Riemannian theory). There are even flamewars over them in internet forums.
Music theory and taxonomy are more like maps of contingent landscapes than a theory predicting things beyond the observed phenomena.
Biological taxonomy differs from music theory in two important ways. Firstly, the organisms exist independently of the taxonomical activity. In contrast, practitioners of music—composers and performers—are influenced by the theories. They create music within the frameworks that were derived from the music before them, or deliberately react against them and invent new theories to compose new sorts of music in, such as serialism.
Secondly, the development of biology has put empirical foundations underneath the taxonomical activity. (Here is a history of that process.)
[ETA: Sometimes to the effect of exposing some of the concepts as purely conventional. We know what physically underlies the concept of a species, and also know how fuzzy it can get. For other parts it has demonstrated that, e.g. there is no such thing as a genus, or a family, or a kingdom, any more than one can empirically distinguish twigs, branches and boughs: all the levels above species are just conventions convenient to have.]
No such empirical foundation exists for music. Composers are free to flout anyone’s theory of what they are doing, and are ultimately bound only by the limits of the human ear.
So, I can read “cultural theory” and “critical theory” as being the same sort of activity as music theory. But that is at the expense of reading them as making true statements about something outside of themselves. They are descriptive maps, or rather, a multitude of competing and conflicting maps of the same territory. In fact, the activity of cultural theory might even be considered to be more like musical performance than musical theory. One does not go to a lecture in the area of cultural theory, critical studies, semiotics, and the like to learn true things, but to experience an intellectually entertaining assemblage of ideas floating as independently of the real world as an interpretation of a Rorschach blot.
What do you think? And where does this leave systems theory? If systems theory were like to musical performance I would have little use for it, but I think its practitioners intend a more solid connection to the real world than that. Perhaps it is like taxonomy? Or something else?
Everything I’ve encountered on “systems theory” suggests to me that there is no such thing. The writings generally consist of a large quantity of words about the definitions of other words, but no mathematics and no predictions that were not already there before pulling it into the ambit of “systems”.
Are there any counterexamples to this?
I consider control theory to be a part of systems theory and given that you give a talk on the virtues of control theory I think you value it. Apart from that my thoughts about the space:
If you look at Seth Roberts’s Shagri-La diet it’s based on systems thinking. It gives different answers than the standard nutritional paradgim which thinks that losing weight is about linear effect of eating less and exercising more.
You don’t need any math for understanding the Shangri-La diet but you do need a certain intellectual framework that considers systems to be important.
Mathematical predictions are only one aspect a theory can provide. Systems theory provides phenomenlogical primitives that can prevent you from dismissing the Shangri-La as strange and obviously crazy. It provides you with a better ontology that allows you to consider new solutions.
Hakob Barseghyan describes in his HPS100 course very well how the notion of a life force being important for biology came after Newton changed the accepted ontology and that people basically thought that there’s matter and that matter interacts via forces with other matter. Our current mainstream ontology of physicalism doens’t consider that a place for a vital force exists.
If we go back to Seth Roberts, Seth considers it a good idea to measure the fitness of a human by measuring the reaction time to short math queries. I don’t think Seth wrote anywhere that he’s measuring a “vital force” by doing so, but if you go back in history you find that people have measured the vital force via reaction tests.
Gunnar Stollberg argues that modern systems biology has a concept like the vital force with self-organisation/autopoiesis. A reemergence of vitalism could help explain why a student person who writes down their ideal life or writes about an emotional trauma for 4 days afterwards lead to significantly less sickness as Laura King showed in “The Health Benefits of Writing About Life Goals”.
Systems theory puts us in the position were we don’t have to postulate any paranormal chi for a notion like life force to exist. It doesn’t need math for that task.
I certainly value the theory of control systems, and I think everyone should know its basic concepts. But the real thing looks like this (and all of the stuff that that links to). This is quite unlike what I’ve seen under the banner of “systems”, including some of the references in the OP.
To be more positive, I get from some of your examples the idea that “systems thinking” means “not being stupid.” Specifically, not being the sort of stupid that consists of thinking up a theory that is “obviously” true and failing to see whether it is. I don’t have a problem with that sort of “systems theory”.
But he concludes by admitting that biologists have not taken this up (and briefly, absurdly, considers the hypothesis of a conspiracy to suppress it).
This is where it seems to me to wander off into the fog. Vitalism is an idea with no moving parts. As soon as you have moving parts to explain the phenomena that people pointed to and said “vital force!” as an explanation, the notion of vital force, goes away. Likewise autopoiesis. The observation that organisms maintain certain variables fixed despite disturbing influences is not explained by giving the phenomenon a name. The thing for a scientist to do is to discover the mechanism. For example, where does a mammal’s body sense its core temperature? How is the reference signal generated, and raised in case of fever? And so on. When the whole story is known, we know not merely that it self-regulates, but how.
Not being stupid in way where the majority of our society is stupid.
Just as the majority of nutrition scientists haven’t taken up Seth Robert’s Shangri-La diet or did research in that direction.
When hearing the discussion of a topic like homeopathy I never see references to the fact that quizing a patient for two hours for the trauma of his life instead of talking with him for 5 minutes has a good chance to have benefitial health effects. It’s well replicated that writing about your trauma’s creates health benefits. That’s because of the paradigm in which our medicine is practiced.
Calling that mysterious variable that get’s raised by writing about trauma “vital force” might not be a good explanation but once you go that step you can ask new research questions. If you allow people to simple call it vital force you allow new questions. Is there a way to measure it? Can we measure the “vital force” a day after the trauma writing and see whether the writing worked at raising the vital force? Can we then use that score to predict days of illness?
If you believe that’s the only thing scientists are allowed to do then they won’t be able to do work where predictions can be made but where the underlying mechanism is illusive.
Would you forbid psychologists from talking about IQ and g because they can’t tell you the mechanism in which IQ/g works?
Currently dualism isn’t dead. Psychologists who work on the mind are allowed to use the concept of IQ without providing an mechanism but biologists are not allowed to do something similar with a life force metric.
Just be complete, no I don’t think that there’s a conspiracy that forbids biologists from doing so. It’s just that the paradigm and people being stupid. I think systems theory provides a way out.
It depends what they say about it. There are observable and fairly robust statistical correlations from which g can be constructed, and g can be used to make (rather weak in the individual case) predictions of various sorts. That does not make g a thing. I predict that if we ever find out how the brain works, g will not be a part of that mechanism, just a rough statistical regularity, as it is at present.
If life force is going to be the same sort of thing as g, it might be useful in medicine, which to a substantial and increasing extent is based on statistical trials with little knowledge of mechanisms. But I don’t see it as useful for research into how things work.
I think that “finding out how things work” should not be the goal of science. The goal should be to develop models that provide reliable and useful predictions.
Newton postulate gravitation as a force without telling his audience how gravity works. The fact that Newton couldn’t explain that slowed down adoption of his model, yet accepting his model brought science a huge step forward. Even on many issues that are about research into how things work. Theories that provide additional predictive power help science advance even if their proponents can’t explain everything from the ground up.
To get back to system theory. It allows us to say: “Emergence” when we don’t know how something come about and still work with what comes about. When someone tells you that homeopathy doesn’t work because there are no infinitively small numbers of atoms he has a valid argument. Our ontological framework doesn’t allow the infinitively small numbers of atoms. People who have never heard of systems theory and subfield of it like control theory will have a similar reaction to the Shangri-La diet as to homeopathy. The ontology doens’t allow for it.
System theory then allows for an ontology in which it can happen. That’s valuable. When you go through a specific example you can also think about what the various words of system theory might be when you apply it to the system you study. That provides you with a structure to model the problem even if you don’t have enough data for mathematical modelling.
We have no idea how the set point for blood pressure is that in the human body, but it’s worthwhile to think of blood pressure regulation as a sytem that has a set point even if we don’t know how that is set. From a medical standpoint we can think differently about the system through looking at it with the lense of system theory.
To get back to the life force, it’s good when we get more free and focus on increasing the predictive power of our models without worrying too much about whether we know at the moment the mechanism behind a certain value. Sometimes it can even be useful to free our concepts from wanting to explain mechanisms. A term like Shaken Baby syndrome can be quite problematic if you find out that 1% of the cases of babies with “Shaken baby syndrome” weren’t shaken.
“Discover”, not “have discovered”. Newton’s work was a step; Einstein finding more of a mechanism was a further step.
It’s difficult to get the latter without the former, if you want to make successful way-out-of-sample predictions. Otherwise, you’re stuck in the morass of trying to find tiny signals and dismissing most of your data as noise.
I think you can do a lot of successful predictions with IQ without knowing the mechanism of IQ. I don’t think you build better IQ tests by going into neuroscience but giving the tests to people and seeing how different variables correlate with each other.
I don’t think that’s true. The present approach of putting compounds through massive screening arrays based on theoretical reasoning that it’s good to hit certain biochemical pathways is very noise-laden and produces a lot of false positives. >90% of drug candidats that get put into trials don’t work out.
I think “system theory” used to be called cybernetics and (in its contemporary form) was basically invented by Norbert Wiener.
This might be splitting hairs, but I would probably call it a “framework” in the sense that it provides a context (e.g. language and concepts) within which more specific “theories” exist. Which theory, for example, would consider the similarities between feedback mechanisms in financial markets and in ecological systems?
Dynamic systems. I am not convinced it gains from being associated with a wider “systems theory”.
Of perhaps, like Molière’s bourgeois gentilhomme discovering that he had been speaking prose all his life, the message is that “systems thinking” is what I have always been doing?
Might be :-) I think cybernetics / system theory basically dissolved into a set of disciplines or theories, much like natural philosophy did a long time ago or, say, geography did fairly recently.
I think of it more like a particular lens from which to view problems, i.e. it is an alternative to reductionism. But, perhaps it’s most useful aspect is that it allows the development of techniques which can be used to simulate complex systems. Ludwig von Bertalanff described the set of theories that together comprise the framework of systems thought in the following passage:
If you want to deep dive into complex systems, I found this to be useful.
My impression is that there are a few core ideas which get turned into frameworks by different people every few years because rediscovery + the generative effect are more fun/epiphany inducing than reviewing the entire literature.
WRT predictions: systems theory is about modelling, and modelling is always making implicit predictions about the causal structure of the system. The better ‘systems theory frameworks’ encourage turning these into explicit predictions/tests.
You seem to be tacit assuming that only a quantiative, predictive theory is a theory at all, but as far as general usage goes, the horse has bolted, because we have critical theory, cultural theory and other such handwavey things.
Many things are called theories, but they are not all the same sort of thing. I know little of critical theory or cultural theory, but I have a very slight acquaintance with music theory, so let me say what sort of thing that appears to be to me, and ask if these other “theories”, including systems theory, are a similar sort of thing.
Musical theory is not the same sort of thing as the theory of Newtonian mechanics. It is more like (pre-neo-Darwinian) biological taxonomy (although different in important ways I’ll come to). That is, it is an activity of classifying things into a framework, a structure of concepts. It makes no predictions, other than that these regularities will continue to be observed. Just as in taxonomy: when you come across a creature that you identify as a heron, you can be sure of a lot of things that you will subsequently observe if you follow it around. But there is no biology here: the classification is based purely on the appearance (perhaps including the results of microscopy) and behaviour of the organism, with no deeper knowledge to tell you how the variety of creatures came to be, or the biochemical processes by which they function. And just as in the history of taxonomy various classification schemes have been proposed, so in music theory there are alternatives to the standard stuff found in elementary textbooks (e.g. Schenkerian theory, Riemannian theory). There are even flamewars over them in internet forums.
Music theory and taxonomy are more like maps of contingent landscapes than a theory predicting things beyond the observed phenomena.
Biological taxonomy differs from music theory in two important ways. Firstly, the organisms exist independently of the taxonomical activity. In contrast, practitioners of music—composers and performers—are influenced by the theories. They create music within the frameworks that were derived from the music before them, or deliberately react against them and invent new theories to compose new sorts of music in, such as serialism.
Secondly, the development of biology has put empirical foundations underneath the taxonomical activity. (Here is a history of that process.)
[ETA: Sometimes to the effect of exposing some of the concepts as purely conventional. We know what physically underlies the concept of a species, and also know how fuzzy it can get. For other parts it has demonstrated that, e.g. there is no such thing as a genus, or a family, or a kingdom, any more than one can empirically distinguish twigs, branches and boughs: all the levels above species are just conventions convenient to have.]
No such empirical foundation exists for music. Composers are free to flout anyone’s theory of what they are doing, and are ultimately bound only by the limits of the human ear.
So, I can read “cultural theory” and “critical theory” as being the same sort of activity as music theory. But that is at the expense of reading them as making true statements about something outside of themselves. They are descriptive maps, or rather, a multitude of competing and conflicting maps of the same territory. In fact, the activity of cultural theory might even be considered to be more like musical performance than musical theory. One does not go to a lecture in the area of cultural theory, critical studies, semiotics, and the like to learn true things, but to experience an intellectually entertaining assemblage of ideas floating as independently of the real world as an interpretation of a Rorschach blot.
What do you think? And where does this leave systems theory? If systems theory were like to musical performance I would have little use for it, but I think its practitioners intend a more solid connection to the real world than that. Perhaps it is like taxonomy? Or something else?