This extensively revised 4th edition comprehensively covers information retrieval from a biomedical and health perspective, providing an understanding of the theory, implementation, and evaluation of information retrieval systems in the biomedical and health domain. It features revised chapters covering the theory, practical applications, evaluation and research directions of biomedical and health information retrieval systems. Emphasis is placed on defining where current applications and research systems are heading in a range of areas, including their use by clinicians, consumers, researchers, and others.          Information Retrieval: A Biomedical and Health Perspective provides a practically applicable guide to range of techniques for information retrieval and is ideal for use by both the trainee and experienced biomedical informatician seeking an up-to-date resource on the topic.