Search Results for author: Leopoldo Bertossi

Found 28 papers, 0 papers with code

Reasoning about Counterfactuals and Explanations: Problems, Results and Directions

no code implementations25 Aug 2021 Leopoldo Bertossi

There are some recent approaches and results about the use of answer-set programming for specifying counterfactual interventions on entities under classification, and reasoning about them.

Second-Order Specifications and Quantifier Elimination for Consistent Query Answering in Databases

no code implementations19 Aug 2021 Leopoldo Bertossi

Consistent answers to a query from a possibly inconsistent database are answers that are simultaneously retrieved from every possible repair of the database.

Extending Sticky-Datalog+/- via Finite-Position Selection Functions: Tractability, Algorithms, and Optimization

no code implementations2 Aug 2021 Leopoldo Bertossi, Mostafa Milani

We propose a bottom-up QA algorithm for programs in the class sch(S), for a general selection function S. As a particular case, we obtain a polynomial-time QA algorithm for JWS and weakly-sticky programs.

Answer-Set Programs for Reasoning about Counterfactual Interventions and Responsibility Scores for Classification

no code implementations21 Jul 2021 Leopoldo Bertossi, Gabriela Reyes

We describe how answer-set programs can be used to declaratively specify counterfactual interventions on entities under classification, and reason about them.

Score-Based Explanations in Data Management and Machine Learning: An Answer-Set Programming Approach to Counterfactual Analysis

no code implementations19 Jun 2021 Leopoldo Bertossi

We describe some recent approaches to score-based explanations for query answers in databases and outcomes from classification models in machine learning.

On the Complexity of SHAP-Score-Based Explanations: Tractability via Knowledge Compilation and Non-Approximability Results

no code implementations16 Apr 2021 Marcelo Arenas, Pablo Barceló, Leopoldo Bertossi, Mikaël Monet

While in general computing Shapley values is an intractable problem, we prove a strong positive result stating that the $\mathsf{SHAP}$-score can be computed in polynomial time over deterministic and decomposable Boolean circuits.

Declarative Approaches to Counterfactual Explanations for Classification

no code implementations15 Nov 2020 Leopoldo Bertossi

In relation to the outcome of the model, the resulting counterfactual entities serve as a basis for the definition and computation of causality-based explanation scores for the feature values in the entity under classification, namely "responsibility scores".

General Classification

Score-Based Explanations in Data Management and Machine Learning

no code implementations24 Jul 2020 Leopoldo Bertossi

We describe some approaches to explanations for observed outcomes in data management and machine learning.

An ASP-Based Approach to Counterfactual Explanations for Classification

no code implementations28 Apr 2020 Leopoldo Bertossi

We propose answer-set programs that specify and compute counterfactual interventions as a basis for causality-based explanations to decisions produced by classification models.

General Classification

Causality-based Explanation of Classification Outcomes

no code implementations15 Mar 2020 Leopoldo Bertossi, Jordan Li, Maximilian Schleich, Dan Suciu, Zografoula Vagena

We propose a simple definition of an explanation for the outcome of a classifier based on concepts from causality.

General Classification

Repair-Based Degrees of Database Inconsistency: Computation and Complexity

no code implementations27 Sep 2018 Leopoldo Bertossi

We propose a generic numerical measure of the inconsistency of a database with respect to a set of integrity constraints.

Measuring and Computing Database Inconsistency via Repairs

no code implementations24 Apr 2018 Leopoldo Bertossi

We propose a generic numerical measure of inconsistency of a database with respect to a set of integrity constraints.

Datalog: Bag Semantics via Set Semantics

no code implementations17 Mar 2018 Leopoldo Bertossi, Georg Gottlob, Reinhard Pichler

This use of Datalog$^\pm$ is extended to give a set semantics to duplicates in Datalog$^\pm$ itself.

Translation

Specifying and Computing Causes for Query Answers in Databases via Database Repairs and Repair Programs

no code implementations4 Dec 2017 Leopoldo Bertossi

In this work, answer-set programs that specify repairs of databases are used as a basis for solving computational and reasoning problems about causes.

The Causality/Repair Connection in Databases: Causality-Programs

no code implementations17 Apr 2017 Leopoldo Bertossi

In this work, answer-set programs that specify repairs of databases are used as a basis for solving computational and reasoning problems about causes for query answers from databases.

Ontological Multidimensional Data Models and Contextual Data Qality

no code implementations1 Apr 2017 Leopoldo Bertossi, Mostafa Milani

Data quality assessment and data cleaning are context-dependent activities.

The Ontological Multidimensional Data Model

no code implementations10 Mar 2017 Leopoldo Bertossi, Mostafa Milani

In this extended abstract we describe, mainly by examples, the main elements of the Ontological Multidimensional Data Model, which considerably extends a relational reconstruction of the multidimensional data model proposed by Hurtado and Mendelzon by means of tuple-generating dependencies, equality-generating dependencies, and negative constraints as found in Datalog+-.

Enforcing Relational Matching Dependencies with Datalog for Entity Resolution

no code implementations21 Nov 2016 Zeinab Bahmani, Leopoldo Bertossi

Entity resolution (ER) is about identifying and merging records in a database that represent the same real-world entity.

Entity Resolution

Causes for Query Answers from Databases: Datalog Abduction, View-Updates, and Integrity Constraints

no code implementations6 Nov 2016 Leopoldo Bertossi, Babak Salimi

In this work we establish precise connections between QA-causality and both abductive diagnosis and the view-update problem in databases, allowing us to obtain new algorithmic and complexity results for QA-causality.

Extending Weakly-Sticky Datalog+/-: Query-Answering Tractability and Optimizations

no code implementations10 Jul 2016 Mostafa Milani, Leopoldo Bertossi

We apply the magic-sets rewriting in combination with the proposed QA algorithm for the optimization of QA over JWS programs.

Consistency and Trust in Peer Data Exchange Systems

no code implementations6 Jun 2016 Leopoldo Bertossi, Loreto Bravo

We propose and investigate a semantics for "peer data exchange systems" where different peers are related by data exchange constraints and trust relationships.

A Hybrid Approach to Query Answering under Expressive Datalog+/-

no code implementations22 Apr 2016 Mostafa Milani, Andrea Cali, Leopoldo Bertossi

Datalog+/- is a family of ontology languages that combine good computational properties with high expressive power.

Causes for Query Answers from Databases, Datalog Abduction and View-Updates: The Presence of Integrity Constraints

no code implementations20 Feb 2016 Babak Salimi, Leopoldo Bertossi

In this work we further investigate connections between query-answer causality and abductive diagnosis and the view-update problem.

ERBlox: Combining Matching Dependencies with Machine Learning for Entity Resolution

no code implementations7 Feb 2016 Zeinab Bahmani, Leopoldo Bertossi, Nikolaos Vasiloglou

Entity resolution (ER), an important and common data cleaning problem, is about detecting data duplicate representations for the same external entities, and merging them into single representations.

Entity Resolution

ERBlox: Combining Matching Dependencies with Machine Learning for Entity Resolution

no code implementations25 Aug 2015 Zeinab Bahmani, Leopoldo Bertossi, Nikolaos Vasiloglou

Entity resolution (ER), an important and common data cleaning problem, is about detecting data duplicate representations for the same external entities, and merging them into single representations.

Entity Resolution

From Causes for Database Queries to Repairs and Model-Based Diagnosis and Back

no code implementations1 Jul 2015 Leopoldo Bertossi, Babak Salimi

In this work we establish and investigate connections between causes for query answers in databases, database repairs wrt.

Query-Answer Causality in Databases: Abductive Diagnosis and View-Updates

no code implementations13 Jun 2015 Babak Salimi, Leopoldo Bertossi

Causality has been recently introduced in databases, to model, characterize and possibly compute causes for query results (answers).

Tractable Query Answering and Optimization for Extensions of Weakly-Sticky Datalog+-

no code implementations13 Apr 2015 Mostafa Milani, Leopoldo Bertossi

We consider a semantic class, weakly-chase-sticky (WChS), and a syntactic subclass, jointly-weakly-sticky (JWS), of Datalog+- programs.

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