A large class of entity extraction tasks from text that is either semistructured or fully unstructured may be addressed by regular expressions, because in many practical cases the relevant entities follow an underlying syntactical pattern and this pattern may be described by a regular expression. In this work, we consider the long-standing problem of synthesizing such expressions automatically, based solely on examples of the desired behavior. We present the design and implementation of a system capable of addressing extraction tasks of realistic complexity. Our system is based on an evolutionary procedure carefully tailored to the specific needs of regular expression generation by examples. The procedure executes a search driven by a multiobjective optimization strategy aimed at simultaneously improving multiple performance indexes of candidate solutions while at the same time ensuring an adequate exploration of the huge solution space. We assess our proposal experimentally in great depth, on a number of challenging datasets. The accuracy of the obtained solutions seems to be adequate for practical usage and improves over earlier proposals significantly. Most importantly, our results are highly competitive even with respect to human operators. A prototype is available as a web application at <;uri xlink:type="simple">http://regex.inginf.units.it<;/uri>.

A system that can produce regular expressions from user-provided examples performed with high precision and recall in 12 text-extraction tasks from real-world datasets, demonstrating the effectiveness of text extraction based on genetic programming.

We consider the problem of matching the topics of a scientific paper with those of possible publication venues for that paper. While every researcher knows the few top-level venues for his specific fields of interest, a venue recommendation system may be a significant aid when starting to explore a new research field. We propose a venue recommendation system which requires only title and abstract, differently from previous works which require full-text and reference list: hence, our system can be used even in the early stages of the authoring process and greatly simplifies the building and maintenance of the knowledge base necessary for generating meaningful recommendations. We assessed our proposal using a standard metric on a dataset of more than 58000 papers: the results show that our method provides recommendations whose quality is aligned with previous works, while requiring much less information from both the paper and the knowledge base.