40,210 research outputs found
Tests based on characterizations, and their efficiencies: a survey
A survey of goodness-of-fit and symmetry tests based on the characterization
properties of distributions is presented. This approach became popular in
recent years. In most cases the test statistics are functionals of
-empirical processes. The limiting distributions and large deviations of new
statistics under the null hypothesis are described. Their local Bahadur
efficiency for various parametric alternatives is calculated and compared with
each other as well as with diverse previously known tests. We also describe new
directions of possible research in this domain.Comment: Open access in Acta et Commentationes Universitatis Tartuensis de
Mathematic
Comparing Two Contaminated Samples
We consider the problem of testing whether two samples of contaminated data,
possibly paired, are from the same distribution. Is is assumed that the
contaminations are additive noises with known moments of all orders. The test
statistic is based on the polynomials moments of the difference between
observations and noises. . A data driven selection is proposed to choose
automatically the number of involved polynomials. We present a simulation study
in order to investigate the power of the proposed test within discrete and
continuous cases. A real-data example is presented to demonstrate the method
Of course we share! Testing Assumptions about Social Tagging Systems
Social tagging systems have established themselves as an important part in
today's web and have attracted the interest from our research community in a
variety of investigations. The overall vision of our community is that simply
through interactions with the system, i.e., through tagging and sharing of
resources, users would contribute to building useful semantic structures as
well as resource indexes using uncontrolled vocabulary not only due to the
easy-to-use mechanics. Henceforth, a variety of assumptions about social
tagging systems have emerged, yet testing them has been difficult due to the
absence of suitable data. In this work we thoroughly investigate three
available assumptions - e.g., is a tagging system really social? - by examining
live log data gathered from the real-world public social tagging system
BibSonomy. Our empirical results indicate that while some of these assumptions
hold to a certain extent, other assumptions need to be reflected and viewed in
a very critical light. Our observations have implications for the design of
future search and other algorithms to better reflect the actual user behavior
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