The O*NET database contains several hundred variables that represent descriptors of work and worker characteristics. In order to remain current with occupational changes, the O*NET program collects data on a continuous basis. O*NET is also continually working to improve the quality of the data, which sometimes involves changing the variables for which data are collected. The Revision of O*NET Data Collection Instruments documents changes made to the O*NET data collection instruments used to collect data beginning in 1999. The response rate using these revised instruments was significantly improved compared to previous versions.
The changes to data variables documented in this report are not reflected in either the O*NET 98 database or the O*NET 3.1 database, but are reflected in the O*NET 4.0 database and subsequent database versions. Please note the updated appendices, especially Appendix A (changes in titles and wording of definitions in the questionnaires).