KLD was under contract to DIGITALiBiz, Inc. to support its work for NHTSA revising data veracity measures for the Crash Investigation Sampling System from those used in the NASS Continuous Data System (CDS).
For each of its data collection systems, NHTSA created a series of algorithms which assessed accuracy through variable range limits, multi-variable comparisons, and logic tests. These edit checks were written for the CDS in Structured Query Language specific for the Oracle database. This programming was organized into groups applicable for vehicle, occupant and crash data, testing the validity and relationships within and among the groups.
After the conversion to Oracle, the writing of these edits was vital to the quality of the data produced by the system. The creation and testing of the programming was a collaborative effort between NHTSA staff and KLD personnel.
KLD accumulated a wealth of experience in this area, assisting in the creation of new checks and adaptation of existing checks for database changes, addition, and removal of variables. After NHTSA changed from Oracle to SQL Server as a database platform, KLD personnel converted a large number of the CDS Oracle based checks into SQL Server in the next two years, using the model database and active data to write and test the accuracy and effectiveness of these checks.