Research paper by Tope Omitola, Andre Freitas, Edward Curry, Sean ORiain, Nicholas Gibbins and Nigel Shadbolt on a formal model of IDT (Interactive Data Transformation). IDT tools allow re-purposing of data by standardisation of heterogeneous data sets. They can also perform data quality assurance. The paper discusses the implementation and validation of the model on the IDT platform Google Refine.