| Abstract |
Monitoring involves the collection, analysis and evaluation of information over time. For
many professionals, monitoring is a central aspect of their work. For example, policy-
makers closely watch the e®ects of their current policies to set the right course for reform.
Likewise, physicians monitor the well-being of their patients to adjust their treatments
when necessary. In business, ¯nancial investors monitor stock prices and interest rates to
optimally time their investments, while marketing managers watch their customers' needs
and wants to frame their marketing e®orts.
The above examples illustrate that monitoring is crucial in many disciplines to make
the right decisions at the right moment. For this reason, there has always been a need for
improved monitoring methods. With the advent of increasingly powerful computers and
advanced analytical techniques, monitoring systems can nowadays process large amounts
of information and have become fully automated where desired. A large body of moni-
toring methods originate from academics. Especially during the past four decades, many
insights from various ¯elds such as economics, statistics, psychometrics and econometrics
found their way into everyday monitoring practice. With the overwhelming availability
of information in some cases, but also the intrinsic lack of information in other cases, the
area is continuously faced with new and highly relevant research challenges.
The aim of this thesis is to contribute to the development of new monitoring methods
by o®ering potential solutions to some of these challenges. The challenges studied in this
thesis arise from all three aspects of monitoring, that is from the collection, the analysis as
well as from the evaluation of information. |