8

I'm looking for an example sentence with a non-projective dependency parse. It doesn't have to be in English, though such an example would be nice.

  • 2
    What are you looking for? – dainichi May 5 '13 at 15:33
  • 2
    I think you'll have to indicate what you mean by a "sentence with a non-projective dependency parse", because that's not really a standard term, no matter what your professors said. An example would be nice, especially if it contrasted with an example of a sentence that was minimally distinct in that it does have a projective dependency parse, or a non-projective non-dependency parse, or something else that would allow triangulation. – jlawler May 5 '13 at 16:05
6

The paper, Non-projective Dependency Parsing using Spanning Tree Algorithms has a few examples of non-projective dependency trees.

non projective tree

Note that dependency graphs are (1) not a formalism and (2) not standardized, so each researcher may re-define what happens in dependencies. Some of those dependency graphs are not even trees. Refer Generating Typed Dependency Parses from Phrase Structure Parses.

dependency graph

  • how do you draw these trees in LaTeX?? – CpILL Jul 13 '15 at 10:50
  • 2
    @CpILL I'm not really big on LaTeX but you can look here: en.wikibooks.org/wiki/LaTeX/Linguistics – prash Jul 13 '15 at 16:32
  • @prash So the first sentence is non-projective only because of word 'yesterday'? – Amir Dec 5 '16 at 13:25
  • @Amir: It's a combination of two factors, 'yesterday' and 'which was a Yorkshire Terrier'. – prash Dec 5 '16 at 16:50
5

Here's a different way to look at it: you draw the dependency tree above the sentence with each node aligned with the corresponding word in the sentence, draw a line between the words in the tree and their correspondent in the sentence, and check whether there are any lines intersecting.

The structure below is for the French sentence À qui veux-tu que Pierre parle ? (lit. To whom want you that Peter talks?, 'Who do you want Peter to talk to?'). This sentence is non-projective because à qui has sort of "emancipated" from its governor to position itself relatively to veux. The dependency between parle and à crosses three node projections.

enter image description here

  • Yes, nice example. – Tim Osborne Feb 18 '15 at 1:12
0

Here is a short English example from the paper Non-Projective Dependency Parsing in Expected Linear Time:

Dependency tree for an English sentence (non-projective).

Or, if you want it in Universal Dependencies,

Universal Dependencies non-projective tree for an English sentence.

Here is the LaTeX code to generate the latter:

\begin{dependency}
    \begin{deptext}[column sep=1.2em]
        A \& hearing \& is \& scheduled \& on \& the \& issue \& today \\
    \end{deptext}
    \deproot{4}{root}
    \depedge{2}{1}{det}
    \depedge{4}{2}{nsubj:pass}
    \depedge{4}{3}{aux:pass}
    \depedge{7}{5}{case}
    \depedge{7}{6}{det}
    \depedge[edge start x offset=-6pt]{2}{7}{nmod}
    \depedge[edge slant=6pt]{4}{8}{nmod:tmod}
\end{dependency}

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.