The object of data mining is massiv

The object of data mining is massive data, which is generally stored in a database. However, these data are often not suitable for direct mining, and data preparation work is required. Data preparation generally includes data selection (select relevant data), data purification (remove noise data), data speculation (estimate missing data), data conversion (interconversion between discrete value data and continuous value data, and grouping of data values Classification, calculation combination between data items, etc.), data reduction (reduce the amount of data). These tasks are often prepared when the data warehouse is generated. Data preparation is the first step of data mining. Whether this step is done well will affect the efficiency and accuracy of data mining and the effectiveness of the final model.