Systems for metadata: documenting scientific databases

The SIPP ACCESS information system was organized into a relational database. RDBMSs automatically provide system catalogs of relations and attributes, giving unique labels to every distinct measure in SIPP. Five features of additional metadata created are noteworthy. The data dictionary for all repeated measures was concatenated in a single document that could be retrieved by label, or by knowledge of naming conventions on the questionnaire. The relational calculus was used to describe the graph of the questionnaire. The third innovation consisted of a relation on relations, Tablelist, that described the content of each relation and the unit of analysis to which it referred. A bibliographic database of technical memoranda and reports derived from the data was created. The final innovation was to create a reporting system for the logged use of different parts of the database, communication with the staff, and the progress of scientific findings and errors detected through SIPP ACCESS