🤖 AI Summary
Existing causal abstraction frameworks struggle with lossy abstractions—i.e., many-to-one mappings—because the conventional “abstraction invariance” assumption fails when multiple low-level interventions map to a single high-level intervention. To address this, we propose the **projection abstraction framework**, which relaxes this assumption and establishes the first rigorous causal abstraction theory for lossy representations. Our approach constructs learnable projection mappings that preserve causal semantics when transforming from complex, low-dimensional models to concise, high-dimensional abstract models. We introduce a graph-structural identifiability criterion enabling high-level causal structure inference from finite observational data. Theoretically, we prove cross-level transferability of the framework for observational, interventional, and counterfactual queries. Empirical evaluation on high-dimensional image domains demonstrates accurate recovery of high-level causal structures, significantly enhancing both interpretability and computational efficiency in modeling complex systems. (149 words)
📝 Abstract
The study of causal abstractions bridges two integral components of human intelligence: the ability to determine cause and effect, and the ability to interpret complex patterns into abstract concepts. Formally, causal abstraction frameworks define connections between complicated low-level causal models and simple high-level ones. One major limitation of most existing definitions is that they are not well-defined when considering lossy abstraction functions in which multiple low-level interventions can have different effects while mapping to the same high-level intervention (an assumption called the abstract invariance condition). In this paper, we introduce a new type of abstractions called projected abstractions that generalize existing definitions to accommodate lossy representations. We show how to construct a projected abstraction from the low-level model and how it translates equivalent observational, interventional, and counterfactual causal queries from low to high-level. Given that the true model is rarely available in practice we prove a new graphical criteria for identifying and estimating high-level causal queries from limited low-level data. Finally, we experimentally show the effectiveness of projected abstraction models in high-dimensional image settings.