Abstract: P-sets are a new mathematic tool for dynamic information systems.By using the relationship between the outer P-sets and supplemented sets,the concepts of F-distortion data and F-redundant data are proposed.Some theorems are given such as the generation theorem,identification theorem and recovery theorems about F-distortion data.The criterions which -distortion data is restored into normal data are given.Meanwhile,the paper provides the application example.The results provide a new method to study the expanded data in dynamic information system.

Key words: P-sets, F-distortion data, F-redundant data, data generation, data recovery