Re: The (futile?) quest for an automatic paraphrase engine

Interesting but highly sophisticated. Most probably you would need not just a syntactic analysis (how the words are strung together) of the input sentence(s) but a semantic one (the meanings of the words) as well.

The parser has to "understand" the following partial realisations of the original first sentence:

With a population of more than 10.2 million, Seoul, the capital of South Korea, is the world’s largest city in terms of population.

1) Seoul, the capital of South Korea, is the world’s largest city in terms of population with a population of more than 10.2 million.

2) The capital of South Korea, Seoul, is the world’s largest city in terms of population with a population of more than 10.2 million.

3) With a population of more than 10.2 million, the capital of South Korea, Seoul, is the world’s largest city in terms of population.

4) In terms of population, Seoul, the capital of South Korea, is the world’s largest city with a population of more than 10.2 million.

Update

I think the first task of any parser is to recognise that the original first sentence (or its transformed counterparts) has the following constituents:

{With a population of more than 10.2 million}pp, {Seoul}np, {the capital of South Korea}np, {is the world’s largest city}vp {in terms of population}pp.

where

pp->prepositional phrase

np->noun phrase

vp->verb phrase

With some embeddings of constituents:

{With a population {of more than 10.2 million}pp}pp

{the capital {of South Korea}pp}np

Comment on Re: The (futile?) quest for an automatic paraphrase engine

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Re: The (futile?) quest for an automatic paraphrase engine
by jonadab (Parson) on May 17, 2004 at 20:04 UTC

With some embeddings of constituents: {With a population {of more than 10.2 million}pp}pp {the capital {of South Korea}pp}np

It gets worse. It has to understand modifiers -- and know which modifiers are modifying what. For example, the prep. phrase starting with "with a pop..." in the example sentence modifies Seoul, but does "in terms of population" modify "is" adverbially, or does it modify "city" adjectivally? A human can analyze what the sentence would mean each way and conclude that it doesn't matter -- the meaning is the same. You're going to ask AI to figure that out?

Let me lay it on the line: it is *possible* to achieve *sporadic* and *partial* results using an assortment of tricks, but a human is still going to have to go over the results. It would be interesting academic research, but it is currently not of any practical value, because the programming is going to cost more money than the program's going to save you over the obvious solution of hiring a minimum-wage peon to do it instead of writing the program. Yep, that's right: my recommendation to the OP is, hire a work-study student (who is not majoring in your subject area, preferably) to write your questions or whatever, and just forget about programming it -- unless AI research is interesting to you for its own sake.

;$;=sub{$/};@;=map{my($a,$b)=($_,$;);$;=sub{$a.$b->()}} split//,".rekcah lreP rehtona tsuJ";$\=$;[-1]->();print

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