Type signatures can be load-bearing; “type signature” isn’t.
In “(A → B) → A”, Scott Garrabrant proposes a particular type signature for agency. He’s maybe stretching the meaning of “type signature” a bit (‘interpret these arrows as causal arrows, but you can also think of them as function arrows’) but still, this is great; he means something specific that’s well-captured by the proposed type signature.
But recently I’ve repeatedly noticed people (mostly in conversation) say things like, “Does ____ have the same type signature as ____?” or “Does ____ have the right type signature to be an answer to ____?”. I recommend avoiding that phrase unless you actually have a particular type signature in mind. People seem to use it to suggest that two things are roughly the same sort of thing. “Roughly the same sort of thing” is good language; it’s vague and sounds vague. “The same type signature”, on its own, is vague but sounds misleadingly precise.
I thought it would be good to have some examples where you could have a useful type signature, and I asked ChatGPT. I think these are too wishy-washy, but together with the given explanation, they seem to make sense.
Would you say that this level of “having a type signature in mind” would count?
These have different type signatures. A model that predicts well might not explain. People often conflate these roles. Type signatures remind us: different input-output relationships.
Moral Judgments vs Policy Proposals
Moral judgment (deontic): Action → Good/Bad
Policy proposal (instrumental): (State × Action) → (New State × Externalities)
People often act as if “this action is wrong” implies “we must ban it,” but that only follows if the second signature supports the first. You can disagree about outcomes while agreeing on morals, or vice versa.
Interpersonal Feedback
Effective feedback: (Action × Impact) → Updated Mental Model
People often act as if the type signature is just Action → Judgment. That’s blame, not feedback. This reframing can help structure nonviolent communication.
Creativity vs Optimization
Optimization: (Goal × Constraints) → Best Action
Creativity: Void → (Goal × Constraints × Ideas)
The creative act generates the very goal and constraints. Treating creative design like optimization prematurely can collapse valuable search space.
A few of those seem good to me; others seem like metaphor slop. But even pointing to a bad type signature seems much better to me than using ‘type signature’ generically, because then there’s something concrete to be critiqued.
Type signatures can be load-bearing; “type signature” isn’t.
In “(A → B) → A”, Scott Garrabrant proposes a particular type signature for agency. He’s maybe stretching the meaning of “type signature” a bit (‘interpret these arrows as causal arrows, but you can also think of them as function arrows’) but still, this is great; he means something specific that’s well-captured by the proposed type signature.
But recently I’ve repeatedly noticed people (mostly in conversation) say things like, “Does ____ have the same type signature as ____?” or “Does ____ have the right type signature to be an answer to ____?”. I recommend avoiding that phrase unless you actually have a particular type signature in mind. People seem to use it to suggest that two things are roughly the same sort of thing. “Roughly the same sort of thing” is good language; it’s vague and sounds vague. “The same type signature”, on its own, is vague but sounds misleadingly precise.
I thought it would be good to have some examples where you could have a useful type signature, and I asked ChatGPT. I think these are too wishy-washy, but together with the given explanation, they seem to make sense.
Would you say that this level of “having a type signature in mind” would count?
ChatGPT 4o suggesting examples
1. Prediction vs Explanation
Explanation might be:
Phenomenon → (Theory, Mechanism)Prediction might be:
Features → LabelThese have different type signatures. A model that predicts well might not explain. People often conflate these roles. Type signatures remind us: different input-output relationships.
Moral Judgments vs Policy Proposals
Moral judgment (deontic):
Action → Good/BadPolicy proposal (instrumental):
(State × Action) → (New State × Externalities)People often act as if “this action is wrong” implies “we must ban it,” but that only follows if the second signature supports the first. You can disagree about outcomes while agreeing on morals, or vice versa.
Interpersonal Feedback
Effective feedback:
(Action × Impact) → Updated Mental ModelPeople often act as if the type signature is just
Action → Judgment. That’s blame, not feedback. This reframing can help structure nonviolent communication.Creativity vs Optimization
Optimization:
(Goal × Constraints) → Best ActionCreativity:
Void → (Goal × Constraints × Ideas)The creative act generates the very goal and constraints. Treating creative design like optimization prematurely can collapse valuable search space.
7. Education
Lecture model:
Speaker → (Concepts × StudentMemory)Constructivist model:
(Student × Task × Environment) → InsightIf the type signature of insight requires active construction, then lecture-only formats may be inadequate. Helps justify pedagogy choices.
Source: https://chatgpt.com/share/67f836e2-1280-8001-a7ad-1ef1e2a7afa7
A few of those seem good to me; others seem like metaphor slop. But even pointing to a bad type signature seems much better to me than using ‘type signature’ generically, because then there’s something concrete to be critiqued.