1,889 research outputs found
A Boxology of Design Patterns for Hybrid Learning and Reasoning Systems
We propose a set of compositional design patterns to describe a large variety
of systems that combine statistical techniques from machine learning with
symbolic techniques from knowledge representation. As in other areas of
computer science (knowledge engineering, software engineering, ontology
engineering, process mining and others), such design patterns help to
systematize the literature, clarify which combinations of techniques serve
which purposes, and encourage re-use of software components. We have validated
our set of compositional design patterns against a large body of recent
literature.Comment: 12 pages,55 reference
Current and Future Challenges in Knowledge Representation and Reasoning
Knowledge Representation and Reasoning is a central, longstanding, and active
area of Artificial Intelligence. Over the years it has evolved significantly;
more recently it has been challenged and complemented by research in areas such
as machine learning and reasoning under uncertainty. In July 2022 a Dagstuhl
Perspectives workshop was held on Knowledge Representation and Reasoning. The
goal of the workshop was to describe the state of the art in the field,
including its relation with other areas, its shortcomings and strengths,
together with recommendations for future progress. We developed this manifesto
based on the presentations, panels, working groups, and discussions that took
place at the Dagstuhl Workshop. It is a declaration of our views on Knowledge
Representation: its origins, goals, milestones, and current foci; its relation
to other disciplines, especially to Artificial Intelligence; and on its
challenges, along with key priorities for the next decade
Logic-Based Explainability in Machine Learning
The last decade witnessed an ever-increasing stream of successes in Machine
Learning (ML). These successes offer clear evidence that ML is bound to become
pervasive in a wide range of practical uses, including many that directly
affect humans. Unfortunately, the operation of the most successful ML models is
incomprehensible for human decision makers. As a result, the use of ML models,
especially in high-risk and safety-critical settings is not without concern. In
recent years, there have been efforts on devising approaches for explaining ML
models. Most of these efforts have focused on so-called model-agnostic
approaches. However, all model-agnostic and related approaches offer no
guarantees of rigor, hence being referred to as non-formal. For example, such
non-formal explanations can be consistent with different predictions, which
renders them useless in practice. This paper overviews the ongoing research
efforts on computing rigorous model-based explanations of ML models; these
being referred to as formal explanations. These efforts encompass a variety of
topics, that include the actual definitions of explanations, the
characterization of the complexity of computing explanations, the currently
best logical encodings for reasoning about different ML models, and also how to
make explanations interpretable for human decision makers, among others
On Exploiting Hitting Sets for Model Reconciliation
In human-aware planning, a planning agent may need to provide an explanation
to a human user on why its plan is optimal. A popular approach to do this is
called model reconciliation, where the agent tries to reconcile the differences
in its model and the human's model such that the plan is also optimal in the
human's model. In this paper, we present a logic-based framework for model
reconciliation that extends beyond the realm of planning. More specifically,
given a knowledge base entailing a formula and a second
knowledge base not entailing it, model reconciliation seeks an
explanation, in the form of a cardinality-minimal subset of , whose
integration into makes the entailment possible. Our approach, based on
ideas originating in the context of analysis of inconsistencies, exploits the
existing hitting set duality between minimal correction sets (MCSes) and
minimal unsatisfiable sets (MUSes) in order to identify an appropriate
explanation. However, differently from those works targeting inconsistent
formulas, which assume a single knowledge base, MCSes and MUSes are computed
over two distinct knowledge bases. We conclude our paper with an empirical
evaluation of the newly introduced approach on planning instances, where we
show how it outperforms an existing state-of-the-art solver, and generic
non-planning instances from recent SAT competitions, for which no other solver
exists
Scrutinizing XAI using linear ground-truth data with suppressor variables
Machine learning (ML) is increasingly often used to inform high-stakes
decisions. As complex ML models (e.g., deep neural networks) are often
considered black boxes, a wealth of procedures has been developed to shed light
on their inner workings and the ways in which their predictions come about,
defining the field of 'explainable AI' (XAI). Saliency methods rank input
features according to some measure of 'importance'. Such methods are difficult
to validate since a formal definition of feature importance is, thus far,
lacking. It has been demonstrated that some saliency methods can highlight
features that have no statistical association with the prediction target
(suppressor variables). To avoid misinterpretations due to such behavior, we
propose the actual presence of such an association as a necessary condition and
objective preliminary definition for feature importance. We carefully crafted a
ground-truth dataset in which all statistical dependencies are well-defined and
linear, serving as a benchmark to study the problem of suppressor variables. We
evaluate common explanation methods including LRP, DTD, PatternNet,
PatternAttribution, LIME, Anchors, SHAP, and permutation-based methods with
respect to our objective definition. We show that most of these methods are
unable to distinguish important features from suppressors in this setting.Comment: Corrected typo
Logic-based Technologies for Intelligent Systems: State of the Art and Perspectives
Together with the disruptive development of modern sub-symbolic approaches to artificial intelligence (AI), symbolic approaches to classical AI are re-gaining momentum, as more and more researchers exploit their potential to make AI more comprehensible, explainable, and therefore trustworthy. Since logic-based approaches lay at the core of symbolic AI, summarizing their state of the art is of paramount importance now more than ever, in order to identify trends, benefits, key features, gaps, and limitations of the techniques proposed so far, as well as to identify promising research perspectives. Along this line, this paper provides an overview of logic-based approaches and technologies by sketching their evolution and pointing out their main application areas. Future perspectives for exploitation of logic-based technologies are discussed as well, in order to identify those research fields that deserve more attention, considering the areas that already exploit logic-based approaches as well as those that are more likely to adopt logic-based approaches in the future
Interpretable machine learning for genomics
High-throughput technologies such as next-generation sequencing allow biologists to observe cell function with unprecedented resolution, but the resulting datasets are too large and complicated for humans to understand without the aid of advanced statistical methods. Machine learning (ML) algorithms, which are designed to automatically find patterns in data, are well suited to this task. Yet these models are often so complex as to be opaque, leaving researchers with few clues about underlying mechanisms. Interpretable machine learning (iML) is a burgeoning subdiscipline of computational statistics devoted to making the predictions of ML models more intelligible to end users. This article is a gentle and critical introduction to iML, with an emphasis on genomic applications. I define relevant concepts, motivate leading methodologies, and provide a simple typology of existing approaches. I survey recent examples of iML in genomics, demonstrating how such techniques are increasingly integrated into research workflows. I argue that iML solutions are required to realize the promise of precision medicine. However, several open challenges remain. I examine the limitations of current state-of-the-art tools and propose a number of directions for future research. While the horizon for iML in genomics is wide and bright, continued progress requires close collaboration across disciplines
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