DDI Lifecycle allows you to make comparisons of variables across datasets. These comparisons can be recorded in a standardized manner, detailing semantically meaningful relationships between similar variables. This information can form the basis of exploratory tools for researchers.
“Colectica allows you to harmonize variables that measure the same information at different times or among different populations. Colectica uses the DDI Lifecycle represented variable item type to describe this harmonization. Harmonized variables documented in DDI can also be explored and compared on the web using Colectica Portal.”
Colectica - Manage Harmonized Variables