2003-04-25 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:
- Performed consistency checks.
2006-01-18 File CB3686.ALL.PDF was removed from any previous datasets and flagged as a study-level file, so that it will accompany all downloads.