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Controlled Value Lists

Business Overview

CVLs are agreed, finite lists of terms. Each term in each list has a prescribed meaning, which is used for classifying, indexing or searching documents. The 'values' in CVLs have different meanings in different contexts:

  • 'Value' is the meaning in the context of XML programming
  • 'Code' is often the meaning in the context of database information systems
  • 'Vocabulary' is often the meaning in the context of records management.

Technical Overview

Controlled Value Lists have always been an integral part of information processing. Even before database management systems, code tables and lookup lists were used to achieve data quality and integrity. Almost all operational information systems, management information systems and data warehouses rely on some form of lookup tables, code tables or CVLs.

When government agencies operate in isolation they can afford to have independent code tables or CVLs. As soon as agencies start transferring data between systems, they need to establish standards and conversion tables for CVLs, whatever form they take.

Most government agencies already have long established protocols for CVL management and reconciliation. The development of Interoperability in government agencies brings new requirements for CVLs. It also opens up opportunities for agencies to reduce costs and effort in managing CVLs. Some CVLs could be centrally managed by a single agency and used by other agencies without data redundancy or duplication. Some CVLs may require redundancy and duplication, but standardisation and distributed data integrity could benefit all users.

There is another area of interoperability where CVLs have an important role to play. Agencies are moving to internet-based service delivery to the public. These Internet services rely on users entering data into web-based applications where some of the data is in limited value domains. Examples include: gender, city, postcode, payment option, occupation, education level. These limited value domains are usually extensively analysed by Information Architects during design of web-based applications.

Government agency agreement on CVLs is an opportunity for government to offer standardised and predictable user interfaces. This would improve user acceptance and reduce development costs.

Further Details

For more information about CVLs in e-GIF interoperability, see: