[developers] `fragmented' scoping MRSs

Stephan Oepen oe at ifi.uio.no
Sat Jul 19 00:32:38 CEST 2008

hi emily,

> [...] a few examples which seem to fall into an odd category:  The
> "Scoped MRS" option happily returns two fully scoped MRSs, but the
> "Compare Parses" window claims that the underspecified MRS is
> fragmented.

these are actually two independent tests.  the `fragmented' flag that
you (can) see in the tree comparison window, strictly speaking, is not
a report on the MRS, but on its elementary dependency simplification.
this test is unrelated to scopal properties and rather aims to confirm
that the dependency graph is connected, i.e. that each predicate (node)
can be reached via some argument link (arc) from the top node.  imagine
an MRS like the following:

  h_0:def_q(x_0, h_1, h_2)
  h_4:sleep_v(e_0, _)
  h_1 =q h_3

i expect this would scope (i admit i did not test this), but it would
trigger a fragmentation flag at the dependency level.  here, clearly,
it would seem a grammar has failed to bind the ARG1 of `sleep_v', but
in principle i believe it is an open question whether there could be
`meaningful' MRS configurations that legimately map to non-connected
dependency graphs.  for the ERG, at least, i believe dan has used the
fragmentation test as one of several MRS wellformedness indicators.

                                                     all best  -  oe
+++ Universitetet i Oslo (IFI); Boks 1080 Blindern; 0316 Oslo; (+47) 2284 0125
+++     CSLI Stanford; Ventura Hall; Stanford, CA 94305; (+1 650) 723 0515
+++       --- oe at ifi.uio.no; oe at csli.stanford.edu; stephan at oepen.net ---

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