Definitions of Conjunction and Disjunction

Fri Sep 15 02:03:32 UTC 2006

Maite,

As far as disjunction is concerned, there is a difference between exclusive
disjunction and inclusive disjunction. Some languages use different
conjunctions to mark each type of disjunction. If the RST definition that
is used for disjunction states An item presents a (not necessarily
exclusive) alternative for the other(s), then these two different types of
disjuction are lumped into one relation. Perhaps thats fine for English
since we use or to mark both kinds of disjunction and sometimes it may be
ambiguous. But even in English there are ways to differentiate the relations
and/or make the intended function more clear. While I think the definition
as it stands is meant to be inclusive of more than one kind of relation, it
could be interpreted to more narrowly define what we mean by 'and/or' but
not the exclusive use of 'or'.

Ben

________________________________________
From: RST Discussion List [mailto:rstlist at LISTSERV.LINGUISTLIST.ORG] On
Behalf Of Andy Potter
Sent: Thursday, September 14, 2006 8:20 PM
To: RSTLIST at LISTSERV.LINGUISTLIST.ORG
Subject: Re: [RST-LIST] Definitions of Conjunction and Disjunction

Maite,

I don't know how you'll know when a consensus has been reached, but it seems
to me that the definitions recovered by Gisela capture disjunction and
conjunction in a way that is both useful and consistent with the spirit of
RST.

Andy

----- Original Message ----- 
From: Maite Taboada 
To: RSTLIST at LISTSERV.LINGUISTLIST.ORG 
Sent: Wednesday, September 13, 2006 10:39 AM
Subject: Re: [RST-LIST] Definitions of Conjunction and Disjunction

Hi all,

I had a student this summer doing annotations, and she started using the
disjunction and conjunction relations, because they were listed listed in
the RST coder. Below are a few examples of the text that she coded with
those relations. I'm not sure they all apply, since I haven't gone over
them, and she was working without precise definitions (she sort of came up
with definitions based on the examples she found). She found many more
disjunctions than conjunctions, and most, if not all, of them had only 2
nuclei.

As for why the relations are not listed on the web site any more, I simply
don't know. I transferred whatever was on the original site around mid-2004,
and it looks like Bill had removed them by then. I don't know why.

If there's consensus in the list about definitions, I'd be happy to post
them again on the site with examples.

- Maite

---------------------------------------------------------
Examples:

Disjunction
He either had Langdon flashback to a lecture he gave in a class somewhere
(yawn)
or he had two or more characters discuss the issue to death.

Will Peter ever get out,
or will he die in the tower?

She cant get a good nights sleep,
[disjunction, nucleus1] because either Grandma is snoring
[disjunction, nucleus2] or somebody is breaking into her house [sat.,
result] and waking her up.

either that,
or he was specifically looking for a movie contract for this story,

Apparently he just liked the name Betsey
or kept forgetting he'd already used it.

Conjunction
This didn't make me like the story any less
nor did I find it hard to follow-

Disney provides great access to transportation
and every cast member is ready to provide detailed directions and tips for
getting to your desired destination quickly.

---------------------------------------------------------

At 19:20 12/09/2006 +0200, Gisela Redeker wrote:

I have been using the following definitions, which I am pretty sure I got
from Bill Mann's page in 2003:

Relation 

Constraints on each pair of N 

Intention of W 

Conjunction

The items are conjoined to form a unit in which each item plays a comparable
role

R recognizes that the linked items are conjoined

Disjunction

An item presents a (not necessarily exclusive) alternative for the other(s)

R recognizes that the linked items are alternatives

What I like about these definitions is their flexibility: I distinguish
subject matter and presentational uses (for these and for the multi-nuclear
relations of LIST and SEQUENCE). 

I've only now discovered that the current list of definitions on the RST
site no longer includes these -- does anyone know why?

Best regards,
Gisela

Gisela Redeker, Professor
Department of Communication and Information Sciences
Faculty of Arts, University of Groningen
P.O.Box 716, NL-9700 AS Groningen
g.redeker at rug.nl tel:
+31-50-3635973 fax: +31-50-3636855
http://www.let.rug.nl/~redeker

Mick O'Donnell wrote: 

Hi Chris, Jelisaveta, 

  The original document describing was RST: 

William C. Mann and Sandra A. Thompson 1987 "Rhetorical Structure Theory: A
Theory of Text Organization". ISI Technical Report ISI/RS-87-190. 
(available from: http://www.sfu.ca/rst/05bibliographies/report.html) 

It mentions disjunction under multinuclear relations (p73). However, 
from a quick look, I don't think any details are given of this 
relation. 

Conjunction is not mentioned. 
However, there is a Joint relation (p76), which I think is too weak 
for conjunction: Joint asserts no relation between nuclei, while 
Conjunction should assert some relation amongst the nuclei. 

Note however that Bill Mann did add Conjunction 
to the relation sets for both classical and extended RST. 

Mick 

Jelisaveta Safranj wrote: 

Dear Chris, 

I have found something in Discourse Tagging Reference Manual written by Lynn
Carlson and Daniel Marcu. 

Disjunction is a multinuclear relation whose elements can be listed as
alternatives, either positive or negative. 

Examples: 
[Call it a fad.] [Or call it the wave of the future.] 

In the aerobic phase, for instance, lactic acid and lactate are still
produced, [but they are consumed by less active muscles] [or metabolized in
the liver] and so do not accumulate. 

Conjunction is not mentioned at all. 

Hope it helps 
Jelisaveta 

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_____
Maite Taboada
Assistant Professor
Department of Linguistics
Simon Fraser University
8888 University Dr.
Burnaby, B.C. V5A 1S6 
Canada

Tel: 604-291-5585  Fax: 604-291-5659
mtaboada at sfu.ca - http://www.sfu.ca/~mtaboada 