Data Quality: Why Preprocess the data? Measures for data quality: A multidimensional view Accuracy: correct or wrong accurate or not Completeness: not recorded, unavailable, Consistency: some modified but some not, dangling Timeliness: timely update? Believability: how trustable the data are correct? Interpretability how easily the data can be understood?4 Data Quality: Why Preprocess the Data? ◼ Measures for data quality: A multidimensional view ◼ Accuracy: correct or wrong, accurate or not ◼ Completeness: not recorded, unavailable, … ◼ Consistency: some modified but some not, dangling, … ◼ Timeliness: timely update? ◼ Believability: how trustable the data are correct? ◼ Interpretability: how easily the data can be understood?