Generation and search of clustered files

A classified, or clustered file is one where related, or similar records are grouped into classes, or clusters of items in such a way that all items within a cluster are jointly retrievable. Clustered files are easily adapted to broad and narrow search strategies, and simple file updating methods are available. An inexpensive file clustering method applicable to large files is given together with appropriate file search methods. An abstract model is then introduced to predict the retrieval effectiveness of various search methods in a clustered file environment. Experimental evidence is included to test the versatility of the model and to demonstrate the role of various parameters in the cluster search process.