50,009 research outputs found
NCeSS Project : Data mining for social scientists
We will discuss the work being undertaken on the NCeSS data mining project, a one year project at the University of Manchester which began at the start of 2007, to develop data mining tools of value to the social science community. Our primary goal is to produce a
suite of data mining codes, supported by a web interface, to allow social scientists to mine their datasets in a straightforward way and hence, gain new insights into their data. In order to fully define the requirements, we are looking at a range of typical datasets to find out what
forms they take and the applications and algorithms that will be required. In this paper, we will describe a number of these datasets and will discuss how easily data mining techniques can be used to extract information from the data that would either not be possible or would be
too time consuming by more standard methods
Controlling for Unobserved Confounds in Classification Using Correlational Constraints
As statistical classifiers become integrated into real-world applications, it
is important to consider not only their accuracy but also their robustness to
changes in the data distribution. In this paper, we consider the case where
there is an unobserved confounding variable that influences both the
features and the class variable . When the influence of
changes from training to testing data, we find that the classifier accuracy can
degrade rapidly. In our approach, we assume that we can predict the value of
at training time with some error. The prediction for is then fed to
Pearl's back-door adjustment to build our model. Because of the attenuation
bias caused by measurement error in , standard approaches to controlling for
are ineffective. In response, we propose a method to properly control for
the influence of by first estimating its relationship with the class
variable , then updating predictions for to match that estimated
relationship. By adjusting the influence of , we show that we can build a
model that exceeds competing baselines on accuracy as well as on robustness
over a range of confounding relationships.Comment: 9 page
Combining Visual and Textual Features for Semantic Segmentation of Historical Newspapers
The massive amounts of digitized historical documents acquired over the last
decades naturally lend themselves to automatic processing and exploration.
Research work seeking to automatically process facsimiles and extract
information thereby are multiplying with, as a first essential step, document
layout analysis. If the identification and categorization of segments of
interest in document images have seen significant progress over the last years
thanks to deep learning techniques, many challenges remain with, among others,
the use of finer-grained segmentation typologies and the consideration of
complex, heterogeneous documents such as historical newspapers. Besides, most
approaches consider visual features only, ignoring textual signal. In this
context, we introduce a multimodal approach for the semantic segmentation of
historical newspapers that combines visual and textual features. Based on a
series of experiments on diachronic Swiss and Luxembourgish newspapers, we
investigate, among others, the predictive power of visual and textual features
and their capacity to generalize across time and sources. Results show
consistent improvement of multimodal models in comparison to a strong visual
baseline, as well as better robustness to high material variance
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