Approaches to cleaning data sets: a technical comment.

Since each of the methods described has its costs and benefits, more than one method should be used. The combination of methods helps the researcher to obtain an error-free data set. Ideally, value-to-value verification for all data sets is preferred but the multiple entry method is more efficient for large data sets. Each researcher has a definition of large and small data sets. One definition of a large data set is one containing more than 250 records. Such a definition will not be appropriate for all investigators. Therefore, each researcher should balance the allocation of resources needed for a method against the confidence required for the data.