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1.8 Summary
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Invisible data mining: We cannot expect everyone in society to learn and master
data mining techniques. More and more systems should have data mining func-
tions built within so that people can perform data mining or use data mining results
simply by mouse clicking, without any knowledge of data mining algorithms. Intelli-
gent search engines and Internet-based stores perform such invisible data mining by
incorporating data mining into their components to improve their functionality and
performance. This is done often unbeknownst to the user. For example, when pur-
chasing items online, users may be unaware that the store is likely collecting data on
the buying patterns of its customers, which may be used to recommend other items
for purchase in the future.
These issues and many additional ones relating to the research, development, and
application of data mining are discussed throughout the book.
1.8
Summary
Necessity is the mother of invention. With the mounting growth of data in every appli-
cation, data mining meets the imminent need for effective, scalable, and flexible data
analysis in our society. Data mining can be considered as a natural evolution of infor-
mation technology and a confluence of several related disciplines and application
domains.
Data mining is the process of discovering interesting patterns from massive amounts
of data. As a knowledge discovery process, it typically involves data cleaning, data inte-
gration, data selection, data transformation, pattern discovery, pattern evaluation,
and knowledge presentation.
A pattern is interesting if it is valid on test data with some degree of certainty, novel,
potentially useful (e.g., can be acted on or validates a hunch about which the user was
curious), and easily understood by humans. Interesting patterns represent knowl-
edge. Measures of pattern interestingness, either objective or subjective, can be used
to guide the discovery process.
We present a multidimensional view of data mining. The major dimensions are
data, knowledge, technologies, and applications.
Data mining can be conducted on any kind of data as long as the data are meaningful
for a target application, such as database data, data warehouse data, transactional
data, and advanced data types. Advanced data types include time-related or sequence
data, data streams, spatial and spatiotemporal data, text and multimedia data, graph
and networked data, and Web data.
A data warehouse is a repository for long-term storage of data from multiple sources,
organized so as to facilitate management decision making. The data are stored
under a unified schema and are typically summarized. Data warehouse systems pro-
vide multidimensional data analysis capabilities, collectively referred to as online
analytical processing.
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Chapter 1 Introduction
Multidimensional data mining (also called
exploratory multidimensional data
mining) integrates core data mining techniques with OLAP-based multidimen-
sional analysis. It searches for interesting patterns among multiple combinations
of dimensions (attributes) at varying levels of abstraction, thereby exploring multi-
dimensional data space.
Data mining functionalities are used to specify the kinds of patterns or
knowledge
to be found in data mining tasks. The functionalities include characterization and
discrimination; the mining of frequent patterns, associations, and correlations; clas-
sification and regression; cluster analysis; and outlier detection. As new types of data,
new applications, and new analysis demands continue to emerge, there is no doubt
we will see more and more novel data mining tasks in the future.
Data mining, as a highly application-driven domain, has incorporated technologies
from many other domains. These include statistics, machine learning, database and
data warehouse systems, and information retrieval. The interdisciplinary nature of
data mining research and development contributes significantly to the success of
data mining and its extensive applications.
Data mining has many successful applications, such as business intelligence, Web
search, bioinformatics, health informatics, finance, digital libraries, and digital
governments.
There are many challenging issues in data mining research. Areas include mining
methodology, user interaction, efficiency and scalability, and dealing with diverse
data types. Data mining research has strongly impacted society and will continue to
do so in the future.
1.9
Exercises
1.1 What is
data mining? In your answer, address the following:
(a) Is it another hype?
(b) Is it a simple transformation or application of technology developed from databases,
statistics, machine learning, and pattern recognition?
(c) We have presented a view that data mining is the result of the evolution of database
technology. Do you think that data mining is also the result of the evolution of
machine learning research? Can you present such views based on the historical
progress of this discipline? Address the same for the fields of statistics and pattern
recognition.
(d) Describe the steps involved in data mining when viewed as a process of knowledge
discovery.
1.2 How is a data warehouse different from a database? How are they similar?
1.3 Define each of the following data mining functionalities: characterization, discrimi-
nation, association and correlation analysis, classification, regression, clustering, and