Conversion of Digital Quality Control Measures

KLD is currently under contract to DIGITALiBiz, Inc./CORA to support its work for NHTSA revising data veracity measures for the Crash Investigation Sampling System from those used in the National Automotive Sampling System/Continuous Data System (NASS/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. The edit checks as they were called 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.

In the years of CDS, specifically after the conversion to Oracle in 1997, 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.

At the change from NASS to the Crash Data Acquisition System and the change from Oracle to SQL Server as a database platform, NHTSA realized the need to convert the CDS edits to reflect the new database structure. This changeover required not only adapting the checks to the new table and column names but also rewriting the checks to reflect the SQL Server syntax and structure. NHTSA requested KLD to assist in this adaptation in 2015, which KLD has continued to the present.