Data Preparation for Data Mining

Practical experience of data mining has revealed that preparing data is the most time-consuming phase of any data mining project. Estimates of the amount of time and resources spent on data preparation vary from at least 60% to upward of 80% (SPSS, 2002a). In spite of this fact, not enough attention is given to this important task, thus perpetuating the idea that the core of the data mining effort is the modeling process rather than all phases of the data mining life cycle. This article presents an overview of the most important issues and considerations for preparing data for data mining.