Performance Bounds for Pairwise Entity Resolution

Data & Knowledge Engineering, 2017

The task of probabilistic record linkage is to find and link records that refer to the same entity across several disparate data sources. The accurate linking of records (entity resolution) is an important task for the healthcare industry, government, law enforcement, and the private sector, for obvious reasons. However, finding exact matches of an entity can be challenging due to records with typographical, phonetical or other types of errors (noise) found across real-world data sources. Over the years, many comparison functions have been developed to relate pairs of records and produce a similarity score. With a pair of predefined thresholds, one may decide if records pairs match, do not match, or if they require further clerical review. Nevertheless, finding appropriate comparison functions, identity descriptors (fields), threshold values, and efficient classifiers remains a challenging task. In this study, we propose a supervised gradient-based learning model that can adjust its structure and parameters based on matching scores coming from many comparison functions (and applied to many fields), to efficiently classify the records. The design of this structure is transparent, and can potentially allow us to locate which comparison functions and fields are more significant to correctly link the records. To train this structure, we propose a novel performance index that can help learn how to separate matched from non-matched records. Results completed with the use of synthetic datasets affected by different levels of noise show the effectiveness of the algorithm, which can significantly reduce the number of false positives, false negatives, and the number of records selected for review.

Information Systems, 2017

Entity resolution constitutes a crucial task for many applications, but has an inherently quadratic complexity. In order to enable entity resolution to scale to large volumes of data, blocking is typically employed: it clusters similar entities into (overlapping) blocks so that it suffices to perform comparisons only within each block. To further increase efficiency, Meta-blocking is being used to clean the overlapping blocks from unnecessary comparisons, increasing precision by orders of magnitude at a small cost in recall. Despite its high time efficiency though, using Meta-blocking in practice to solve entity resolution problem on very large datasets is still challenging: applying it to 7.4 million entities takes (almost) 8 full days on a modern high-end server. In this paper, we introduce scalable algorithms for Meta-blocking, exploiting the MapReduce framework. Specifically, we describe a strategy for parallel execution that explicitly targets the core concept of Meta-blocking, the blocking graph. Furthermore, we propose two more advanced strategies, aiming to reduce the overhead of data exchange. The comparison-based strategy creates the blocking graph implicitly, while the entity-based strategy is independent of the blocking graph, employing fewer MapReduce jobs with a more elaborate processing. We also introduce a load balancing algorithm that distributes the computationally intensive workload evenly among the available compute nodes. Our experimental analysis verifies the feasibility and superiority of our advanced strategies, and demonstrates their scalability to very large datasets.

Proceedings of the 12th ACM SIGKDD international conference on Knowledge discovery and data mining - KDD '06, 2006

Entity resolution is the problem of reconciling database references corresponding to the same real-world entities. Given the abundance of publicly available databases that have unresolved entities, we motivate the problem of query-time entity resolution: quick and accurate resolution for answering queries over such 'unclean' databases at query-time. Since collective entity resolution approaches-where related references are resolved jointly-have been shown to be more accurate than independent attribute-based resolution for off-line entity resolution, we focus on developing new algorithms for collective resolution for answering entity resolution queries at query-time. For this purpose, we first formally show that, for collective resolution, precision and recall for individual entities follow a geometric progression as neighbors at increasing distances are considered. Unfolding this progression leads naturally to a two stage 'expand and resolve' query processing strategy. In this strategy, we first extract the related records for a query using two novel expansion operators, and then resolve the extracted records collectively. We then show how the same strategy can be adapted for query-time entity resolution by identifying and resolving only those database references that are the most helpful for processing the query. We validate our approach on two large real-world publication databases where we show the usefulness of collective resolution and at the same time demonstrate the need for adaptive strategies for query processing. We then show how the same queries can be answered in real-time using our adaptive approach while preserving the gains of collective resolution. In addition to experiments on real datasets, we use synthetically generated data to empirically demonstrate the validity of the performance trends predicted by our analysis of collective entity resolution over a wide range of structural characteristics in the data.

ArXiv, 2019

One of the most important tasks for improving data quality and the reliability of data analytics results is Entity Resolution (ER). ER aims to identify different descriptions that refer to the same real-world entity, and remains a challenging problem. While previous works have studied specific aspects of ER (and mostly in traditional settings), in this survey, we provide for the first time an end-to-end view of modern ER workflows, and of the novel aspects of entity indexing and matching methods in order to cope with more than one of the Big Data characteristics simultaneously. We present the basic concepts, processing steps and execution strategies that have been proposed by different communities, i.e., database, semantic Web and machine learning, in order to cope with the loose structuredness, extreme diversity, high speed and large scale of entity descriptions used by real-world applications. Finally, we provide a synthetic discussion of the existing approaches, and conclude with...

ACM Computing Surveys

One of the most critical tasks for improving data quality and increasing the reliability of data analytics is Entity Resolution (ER), which aims to identify different descriptions that refer to the same real-world entity. Despite several decades of research, ER remains a challenging problem. In this survey, we highlight the novel aspects of resolving Big Data entities when we should satisfy more than one of the Big Data characteristics simultaneously (i.e., Volume and Velocity with Variety). We present the basic concepts, processing steps, and execution strategies that have been proposed by database, semantic Web, and machine learning communities in order to cope with the loose structuredness , extreme diversity , high speed, and large scale of entity descriptions used by real-world applications. We provide an end-to-end view of ER workflows for Big Data, critically review the pros and cons of existing methods, and conclude with the main open research directions.

Information Fusion, 2019

Entity resolution is an important data association task when fusing information from multiple sources. Oftentimes the information arrives continuously and the entity resolution algorithm needs to efficiently update its solution upon receiving new information. In this work, we introduce an incremental entity resolution algorithm based on a graph partitioning formulation. The developed algorithm is able to handle both incrementally arriving entity references, as well as incrementally arriving information which changes the pairwise similarity scores between the references. New information is handled in a way that allows the algorithm to reconsider past decisions when contradicting information arrives. Because the graph partitioning formulation used is NP-Hard, a heuristic algorithm is developed to produce good solutions, which is also compatible with a blocking technique to limit the number of required comparisons. The algorithm is tested on a variety of datasets (randomly generated and real) and it is shown that allowing the algorithm to consider revised scores and revisit prior decisions offers a substantial improvement to accuracy (approximately 30-40% better F-Score on a natural language dataset), compared to other greedy heuristics on the same set of coefficients. It is also shown that, on a test set with 100 references, the incremental algorithm is up to an order of magnitude faster than a batch algorithm approach that resolves the entire problem.

Extending Database Technology, 2020

JedAI is an open-source toolkit that allows for building and benchmarking thousands of schema-agnostic Entity Resolution (ER) pipelines through a non-learning, blocking-based end-to-end workflow. In this paper, we present its latest release, JedAI 3 , which conveys two new end-to-end workflows: one for budgetagnostic ER that is based on similarity joins, and one for budgetaware (i.e., progressive) ER. This version also adds support for pre-trained word or character embeddings and connects JedAI to the Python data analysis ecosystem. Overall, these enhancements provide JedAI with features offered by no other ER tool, especially in the schema-and domain-agnostic context.

IEEE Transactions on Knowledge and Data Engineering, 2000

Entity Resolution is an inherently quadratic task that typically scales to large data collections through blocking. In the context of highly heterogeneous information spaces, blocking methods rely on redundancy in order to ensure high effectiveness at the cost of lower efficiency (i.e., more comparisons). This effect is partially ameliorated by coarse-grained block processing techniques that discard entire blocks either a-priori or during the resolution process. In this paper, we introduce meta-blocking as a generic procedure that intervenes between the creation and the processing of blocks, transforming an initial set of blocks into a new one with substantially fewer comparisons and equally high effectiveness. In essence, meta-blocking aims at extracting the most similar pairs of entities by leveraging the information that is encapsulated in the block-to-entity relationships. To this end, it first builds an abstract graph representation of the original set of blocks, with the nodes corresponding to entity profiles and the edges connecting the co-occurring ones. During the creation of this structure all redundant comparisons are discarded, while the superfluous ones can be removed by pruning of the edges with the lowest weight. We analytically examine both procedures, proposing a multitude of edge weighting schemes, graph pruning algorithms as well as pruning criteria. Our approaches are schema-agnostic, thus accommodating any type of blocks. We evaluate their performance through a thorough experimental study over three large-scale, real-world datasets, with the outcomes verifying significant efficiency enhancements at a negligible cost in effectiveness.

Proceedings of the third international workshop on Cloud data management - CloudDB '11, 2011

Entity resolution is a crucial step for data quality and data integration. Learning-based approaches show high effectiveness at the expense of poor efficiency. To reduce the typically high execution times, we investigate how learningbased entity resolution can be realized in a cloud infrastructure using MapReduce. We propose and evaluate two efficient MapReduce-based strategies for pair-wise similarity computation and classifier application on the Cartesian product of two input sources. Our evaluation is based on real-world datasets and shows the high efficiency and effectiveness of the proposed approaches.

Computing Research Repository, 2011

There have been several recent advancements in Machine Learning community on the Entity Matching (EM) problem. However, their lack of scalability has prevented them from being applied in practical settings on large real-life datasets. Towards this end, we propose a principled framework to scale any generic EM algorithm. Our technique consists of running multiple instances of the EM algorithm on small neighborhoods of the data and passing messages across neighborhoods to construct a global solution. We prove formal properties of our framework and experimentally demonstrate the effectiveness of our approach in scaling EM algorithms.