Public Release of Structured Data Transformation Language (SDTL) - Version 1.0

The DDI Alliance is pleased to announce the initial public release of Structured Data Transformation Language (SDTL) - Version 1.0.

Structured Data Transformation Language (SDTL) is an independent intermediate language for representing data transformation commands. Statistical analysis packages (e.g., SPSS, Stata, SAS, Python, and R) provide similar functionality, but each one has its own proprietary language. SDTL provides machine-actionable descriptions of variable-level data transformation histories derived from any data transformation language. SDTL uses JSON schemas to represent common operations, such as RECODE, MERGE FILES, and VARIABLE LABELS. Provenance metadata represented in SDTL can be added to documentation in DDI and other metadata standards.

For more information, please see the SDTL product page on the DDI Alliance web site:

Thanks to everyone who contributed to SDTL - Version 1.0, especially George Alter, the C2Metadata Project supported by the Data Infrastructure Building Blocks (DIBBs) program of the National Science Foundation (NSF ACI-1640575), the DDI SDTL Working Group, and the DDI Technical Committee.