One of the significant challenges and opportunities in computer-assisted healthcare is how to improve diagnosis and treatment of patients. With respect to the past, diagnosis and treatment have become more and more difficult because of two major reasons: a global society where people, goods, and, consequently, diseases travel very easily; and a growing awareness and emergence of very rare “orphan” pathologies that affect an extremely small percentage of the population. Physicians are very often required to diagnose and correctly treat diseases that they are not familiar with. Especially in this context, but also with more frequent pathologies, computer assistance can become an essential tool in healthcare, especially if it supports all relevant information such as protocols, exceptions, best practices, condition-specific guidelines, and so on, in addition to diagnosis.
Key Terms in this Chapter
Subsumption: A subsumes B if the set denoted by B is a subset of the set denoted by A ().
Facet: One of several top-level (most general) concepts in a multidimensional taxonomy. In general, facets are independent, and define a set of “orthogonal” conceptual coordinates.
Zoom: A user interface operation that defines a new user focus by OR’ing user-selected concepts and AND’ing them with the previous focus; a reduced taxonomy is then computed and shown to the user.
Taxonomy: A hierarchical organization of concepts going from the most general (topmost), to the most specific concepts. A taxonomy supports abstraction and models subsumption (e.g., IS-A and/or PART-OF) relations between a concept and its father.
Shallow Extension: Of a concept C, denotes the set of documents classified directly under C.
Monodimensional Taxonomy: Taxonomy where an item can be classified under a single concept only.
Extensional Inference Rule: Two concepts A and B are related iff there is at least one item d in the knowledge base which is classified at the same time under A (or under one of A’s descendants) and under B (or under one of B’s descendants).
User Focus: The set of documents corresponding to a user-defined composition of concepts; initially, the entire knowledge base.
Deep Extension: Of a concept C, denotes the shallow extension of C union the deep extension of C’s sons.
Decision Tree: A rooted, ordered, and labeled tree. Given a boolean function on n-variables (tests), a decision tree is a deterministic algorithm for deciding which variable to test next, based on the previously tested variables and the results of their evaluation, until the function’s value can be determined.
Reduced Taxonomy: In a dynamic taxonomy, a taxonomy, describing the current user focus set F, which is derived from the original taxonomy by pruning from it all the concepts not related to F.
Multidimensional Taxonomy: Taxonomy where an item can be classified under several concepts.