by Ihab F. Ilyas (Author), Xu Chu (Author)
Data quality is one of the most
important problems in data management, since dirty data often leads to
inaccurate data analytics results and incorrect business decisions.
Poor
data across businesses and the U.S. government are reported to cost
trillions of dollars a year. Multiple surveys show that dirty data is
the most common barrier faced by data scientists. Not surprisingly,
developing effective and efficient data cleaning solutions is
challenging and is rife with deep theoretical and engineering problems.
This
book is about data cleaning, which is used to refer to all kinds of
tasks and activities to detect and repair errors in the data. Rather
than focus on a particular data cleaning task, we give an overview of
the end-to-end data cleaning process, describing various error detection
and repair methods, and attempt to anchor these proposals with multiple
taxonomies and views. Specifically, we cover four of the most common
and important data cleaning tasks, namely, outlier detection, data
transformation, error repair (including imputing missing values), and
data deduplication. Furthermore, due to the increasing popularity and
applicability of machine learning techniques, we include a chapter that
specifically explores how machine learning techniques are used for data
cleaning, and how data cleaning is used to improve machine learning
models.
This book is intended to serve as a useful reference for
researchers and practitioners who are interested in the area of data
quality and data cleaning. It can also be used as a textbook for a
graduate course. Although we aim at covering state-of-the-art algorithms
and techniques, we recognize that data cleaning is still an active
field of research and therefore provide future directions of research
whenever appropriate.