Recent findings show that online reviews, blogs and
discussion forums on chronic diseases and drugs are becoming important supporting
resources for patients. Extracting information from these substantial bodies of
texts is useful and challenging. We developed a generative probabilistic aspect
mining model (PAMM) for identifying the aspects/topics relating to class labels
or categorical meta-information of a corpus. Unlike many other unsupervised
approaches or supervised approaches, PAMM has a unique feature in that it
focuses on finding aspects relating to one class only rather than finding
aspects for all classes simultaneously in each execution. This reduces the
chance of having aspects formed from mixing concepts of different classes;
hence the identified aspects are easier to be interpreted by people. The
aspects found also have the property that they are class distinguishing: they
can be used to distinguish a class from other classes. An efficient
EM-algorithm is developed for parameter estimation. Experimental results on
reviews of four different drugs show that PAMM is able to find better aspects
than other common approaches, when measured with mean pointwise mutual
information and classification accuracy. In addition, the derived aspects were
also assessed by humans based on different specified perspectives, and PAMM was
found to be rated highest.
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