On-line Error Monitoring for Several Data Structures

We present several examples of programs which ee-ciently monitor the answers from queries performed on data structures to determine if any errors are present. Our paper includes the rst eecient on-line error monitor for a data structure designed to perform nearest neighbor queries. Applications of nearest neighbor queries are extensive and include learning, categorization, speech processing , and data compression. Our paper also discusses on-line error monitors for priority queues and splittable priority queues. On-line error monitors immediately detect if an error is present in the answer to a query. An error monitor which is not on-line may delay the time of detection until a later query is being processed which may allow the error to propagate or may cause irreversible state changes. On-line monitors can allow a more rapid and accurate response to an error.