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Hi all,

I have checked my standard textbook (Wasserman/Faust 1994), looked in
Borgatti/Everett 1992 paper (Regular blockmodels of multiway, multimode
matrices) and elsewhere, including Googling on the web, but I haven't found
any answer so I resort to this list:

How to interpret regular blockmodels based on valued (non-categorical)
directional relations? I haven't seen it being done anywhere. References
anyone?

I understand how to interpret regular blockmodels (i.e blockmodels where the
different positions are established through the notion of regular
equivalence and, for instance, REGE) for dichotomous (binary) values: as
regular equivalence is concerned with equivalent actors having relations to
actors which in turn are equivalent (instead of the strict requirements of
structural equivalence), the submatrices making up inter-positional
relations are interpreted differently in order to create block images.

However, how to do this for valued (non-categorical), directional graph? Is
something like this feasible:

1. Establish discrete role-equivalent positions using regular equivalence
(as implemented in the REGE algorithm)
2. Sort the rows/cols in the original matrix according to positional
membership (i.e create a standard "blockmodel matrix")
3. Dichotomize this matrix, using the mean density of the network as the
cut-off value!
4. Interpret the blockmodel as it is done for regular blockmodels.

Would something like this be feasible?

Number 3 here is of course what might be problematic. Perhaps using some
other cut-off-value? Density of relations within positional submatrices in
some way?

Yours,
Carl
---
Carl Nordlund, BA, PhD student
carl.nordlund(at)humecol.lu.se
Human Ecology Division, Lund university
www.humecol.lu.se

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