Documentation, Codebooks, and Common Errors for Extract
Documentation
The following documentation and codebooks are available in PDF format to help you with using extract.
- Census 2000 1%
- Technical Documentation
- Data Dictionary
- State FIPS Codes
- Appendix G (Occupation, Industry, Language, etc.)
- Appendix L, Relationship Between Super-PUMAs of Place of Work and Super-PUMAs
- 1% Super-PUMA Codes
- Census 2000 5%
- Technical Documentation
- Data Dictionary
- State FIPS Codes
- Appendix G (Occupation, Industry, Language, etc.)
- Appendix L, Relationship Between Super-PUMAs of Place of Work and Super-PUMAs
- 5% Super-PUMA Codes
- Census 1990
- Technical Documentation
- Census 1980
- Technical Documentation
Common Errors with Extract
The most common reasons for Extract to fail are errors in setting up selections and exceeding the system limits on the size of the extract. The following provides more details on these problems. Contact psc-dads@umich.edu if these explanations do not solve the problem.
Errors in setting up selections
Extract is using character comparisons when it makes sample selections. Thus, if one is selecting on age and wants respondents between 9 and 14 years of age, one must specify the age range as follows:
AGE 09 14
Always make sure the sample selection uses as many digits as the width of the variable. If a variable is three columns wide, the low and high values for the selection must each be three columns wide
Exceeding system limits
We have set a limit of 500mb for the size of an extract (uncompressed). If a user takes all cases from a 5% file, the user can only take about 15 to 20 items. [12,000,000 * 44 = 499,000,000]. If a user takes all cases and lots and lots of items, the program will stop writing cases to the extract file, once the 500mb limit is reached.
To see if this has occurred, run a frequency distribution on cases by STATE. One will be missing cases from states that come late in the alphabet (Texas, Virginia, etc.).
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