Editorial: Why H-infinity?

H-infinity is a performance index (norm) measuring the maximum value of a sensitivity or other transfer matrix (which is a function of a complex variable) in the frequency domain. It sounds simple when stated in terms that control engineers can relate to. Why, then, use an obscure mathematical term that is expected to scare engineers away? The author´s objective is to address a critical problem: what is the purpose of a title (and abstract) of a technical paper published in the IEEE Transactions on Automatic Control. He argues that one needs to carefully pick titles so that they can be understood by the typical reader. He does not ask that every paper be accessible, only that every title be accessible. Once the problem of the title is solved engineers can turn their attention to the problem of unreadable abstracts. It is important that every paper use an abstract that is readable by many and that describes the objectives of the paper clearly. The abstract should not contain equations or numbered references. He notes that the abstract of a paper is used for indexing and abstracting (A&I) services, and must be in a form that contains only english characters. After these objectives have been met, engineers may then tackle the problem of the readability and accessibility of the entire paper. If some of these suggestions are followed by our authors, reviewers, and associate editors, we would have made an important step toward a readable and accessible Transactions.