Machine Learning: A Constraint-Based Approach

Some years ago Marco Gori described to me his idea of constraint-based learning. Not much time was required to convince myself that Marco’s point of view was strongly innovative. I enthusiastically accepted his invitation to work together on some aspects related to this subject and so I could give a small contribution to Marco’s “big picture”. When I first saw the monograph, I was impressed by how much work Marco did in recent years on this topic and how clearly he can now present constraint-based learning. The book looks to me like a great “fresco”, in which a large variety of colours and tones have been put together in such a way as to create an exciting overall view. Despite the novelty of the approach described and the fact that research on this subject is quite recent, the material is presented with the elegance and clarity of a classical, well-established theory. Marco has the capability to guide through the various chapters of his "novel", so that the reader can enjoy the book like an enthusiastic journey in the world of constraints. Each concept and each theorem are presented in such a way that they seem to arise in the most natural way and exactly at the right moment. Although some advanced mathematical tools are used, rigour is achieved avoiding heavy formalism and allowing also less technically-oriented readers to enjoy the book. Summing up, this is an excellent monograph dealing with machine learning from an innovative point of view, which lays the foundations of a new theory with strong impact on machine learning applications. It opens the doors to a wide range of research directions. Definitely, Marco’s work is a “must” for researchers and practitioners in machine learning. 

An excellent book on machine learning, with a rigorous yet not heavy formalism, capable of elaborating a unifying view of this discipline from a novel and interesting perspective. A stimulating reading both for students that want to approach this research field, and for experts that want to gain a better understanding of selected topics.