[b-hebrew] Generation grammar and b-hebrew

dwashbur at nyx.net dwashbur at nyx.net
Sat Jun 19 14:50:19 EDT 2010


I know the sum total of nothing about computational linguistics, but I do agree with your 
assessment that too many approaches go top-down and hence are pretty much useless for 
a language like Hebrew.  Just for a single example, 

S -> NP VP

clearly can't handle a Hebrew verbless clause, nor can it handle a clause with a purely 
inflectional subject like the typical wayyiqtol clause.  So as I see it, we need to extract the 
basal phrase structure rules from the data we have rather than trying to impose something 
from another language onto Hebrew.  I would suggest as a starting point

CL -> (P)

That is, a clause is a single predicated unit, whether the predicate (verb, for most purposes) 
is explicit or not.

On 19 Jun 2010 at 20:12, James Christian wrote:

> 
> Hi Eric, traditionally in computational linguistics literature a
> distinction is made between deep 
> and shallow methods. In general, deep methods are considered to be
> rule based while shallow 
> methods are typical driven by statistical information. Obviously,
> shallow methods of generation 
> can be used as well as deep methods and, no surprises, shallow
> methods are performing better 
> than deep methods as in just about every other area of computational
> linguistics. But please 
> don't fall into the classic trap of assuming that shallow methods
> have no rule system. They have 
> a rule system, a very complex one. It just isn't made explicit.
> As you note 'the number of rules could get out of hand'. However, I
> would venture that the very 
> reason shallow methods are working better than deep methods is
> precisely because they have 
> many more implicit rules that give a wider coverage of real
> linguistic high frequency 
> phenomenon. And so I would like to address the following part of
> your statement 'out of hand'. 
> Now I'm not sure exactly what you mean by out of hand. If you are
> assuming that a large amount 
> of rules is a bad thing then I don't necessarily agree. In fact,
> precisely the opposite. The very 
> reason that most modern attempts to define a generative grammar
> aren't as wide coverage as 
> they set out to be is because they are designed to be compact and,
> as a result, over generate. 
> That is not to say I disagree with you entirely. If many rules are
> defined with no control of how 
> they affect each other then unpredictable results will naturally
> arise. My personal experience 
> suggests to me that starting from the specific and working up to the
> generic is a wiser approach 
> to defining a generative grammar. Most attempts to build a
> generative grammar start with a 
> generic sentence rule like: 
> S --> NP VP 
> It comes as no surprise that such attempts generally fail. They are
> starting with a linguistic 
> assumption about the data that they have not extracted from the data
> but rather imposed upon it. 
> This is what I would call a top down approach starting with a
> linguistic assumption about what 
> the top is. It would seem to make more sense to me to adopt a bottom
> up approach with no 
> linguistic assumptions other than letting the data speak for itself.
> That is to say to start by 
> defining rules for the smallest frequently observable phenomenon and
> working your way up to 
> sentence structure, paragraph structure etc. and thus letting the
> data speak for itself what the 
> definition of S is. It may be S --> NP VP, it may be something
> entirely different or it may even be 
> a whole collection of statements. The point is to let the data speak
> for itself. 
> And so, Eric, what I would like you to consider is that it is not
> generative grammar in itself that is 
> the problem. It the method of defining one that may be at fault.
> Please also bear in mind that 
> statistical methods of generative grammar are also rule based. They
> only differ in that their rules 
> system is superior and machine learned from the data. 
> James Christian 


Dave Washburn

http://www.nyx.net/~dwashbur



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