Anna Klimova:
 Coordinate free analysis of contingency 
tables:
history and recent developments
<br><br>
Rövid összefoglalója:
Contingency tables, as frequency distributions on the Cartesian
product of the domains of marginals in the table, are a 
traditional
way of representing categorical data. However, when a sample 
space is
a proper subset of the Cartesian product, not all modeling 
techniques
and inference results apply. The relational models, proposed 
recently
by the authors, are coordinate free and generalize, among 
others,
log-linear models, quasi models, topological models.
<br><br>

A relational model is generated by a class of subsets of cells, 
some
of which may not be induced by marginals of the table, and, 
under the
model, every cell probability is the product of effects 
associated
with subsets the cell belongs to. The properties of the maximum
likelihood estimators depend on the presence of the overall 
effect in
the model. If this effect is present, the usual equivalence 
between
multinomial and Poisson likelihoods holds, and the iterative
proportional fitting procedure can be used to find the maximum
likelihood estimates of the cell frequencies.
<br><br>

In conclusion, the relational model framework is applied to 
address
the question of whether British social mobility is declining 
and to
compare the patterns of occupational mobility in Great Britain 
in 1991
and 2005.