1995-10-30 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.
- Standardized missing values.
- Performed recodes and/or calculated derived variables.
- Checked for undocumented or out-of-range codes.
2000-09-11 The FIPS codes (V70) for Baltimore County and
Baltimore City were corrected in the data because the codes were
erroneously interchanged. The correct codes are: Baltimore County,
24005, and Baltimore City, 24510. Also, the codebook is now available
as a PDF file.
2011-04-14 All parts are being moved to restricted access and will be available only using the restricted access procedures.