Q What is Data mining ?
A Data mining is knowledge discovery in databases. It is extraction of interesting (non-trivial, implicit, previously unknown and potentially useful) information or patterns from data in large databases.
Q What is difference between OLAP and data mining ?
A OLAP - (On-line Analytical Processing )provides you with a very good view of what is happening, but can not predict what will happen in the future or why it is happening where as data mining is group of techniques that find relationships that have not previously been discovered.
Q What are the types of tasks that are carried out during data mining ?
A Data mining involves 2 types of tasks
•Prediction Tasks- Use some variables to predict unknown or future values of other variables
•Description Tasks- Find human-interpretable patterns that describe the data.
Q What do you mean by preprocessing of data in data mining ?
A Before data is mined it has to be preprocessed. It consists of following three stages
Data cleaning - Real world data is dirty so need to be cleaned
Data reduction- Remove data not useful for mining
Data transformation - Syntactic transformation
Q What is Data cleaning ?
A Causes of Dirty Data