Data Mining

                    BsCs    3rd Semester                    DBMS

        Data Mining Questions  and their  Answers

Q # 1 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.
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Q# 2 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.
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Q# 3 What are the functionalities of Data Mining?
•Knowledge Prediction   Data mining uses known data for prediction/forecasting. It is also known as predictive data.

•Knowledge Description - Concrete information gleaned from data is known as data description. It is also known as descriptive data.
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Q# 4 What are  some of the tasks of data mining?

A Following activities are carried out during data mining

• Classification [Predictive]
• Clustering [Descriptive]
• Association Rule Discovery [Descriptive]
• Sequential Pattern Discovery [Descriptive]
• Regression [Predictive]
• Deviation Detection [Predictive]

Q# 5  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# 6 Describe causes and tasks of data cleaing?
A Causes of Dirty Data

• Missing values
• Noisy data (Human/Machine Errors)
• Inconsistent data

            Data cleaning tasks

• Handling missing values
• Identify outliers and smooth out noisy data
• Correct inconsistent data

     Q# 7 Jot down the sources of data mining?

    1_ Data Base
    2_Text Documents
    3_Pictures(images)
    4_Web. 
    Q# 8 How Data Mining helps in prediction ?
                    Data Mining visits and analyzes the previous recorded data on the basis of which it predicts about future.
Q Discuss about Web Mining? 

           
           Web mining is the integration of information gathered by traditional data mining methodologies and techniques with information gathered over the World Wide Web.

Web mining is used to understand customer behavior, evaluate the effectiveness.

Q Discuss about Data Mining Functionalities? 

.       Data mining functionalities are used to specify the kind of patterns to be found in data mining tasks. 

   Data mining tasks:

     Descriptive data mining : characterize the general properties of the data in the database.

   Predictive data mining: perform inference on the current data in order to make predictions.