Implementing ICONS in ERG and Jacy SIG
Participants: Francis, David, oe, Emily
Sanghoun's starting point:
Russian: Need trigger rules for info-str clitics, but they aren't working. Not trying to trigger off of ICONS.
English: I know; Kim is a curious student
ARG2 of know, ARG1 of curious, student are unbound.
Selecting heads are putting in the info-str icons for these, and they have no value.
oe: As I understand it, you put in an info-str constraint for each argument in each clause, even when there's nothing the grammar has to say about that info-str. So the ICONS list will be a very long list. I had anticipated a mechanism where there was a notion of optionality and the ICONS would only be used when there was something contentful to say, e.g., there was topicalization or passivization and the effect is recorded. For English SVO clauses (unmarked order), why should there be anything to be said about information structure? I see why what you do is sound and makes sense, but is there a way to represent the same set of contrasts and same information with fewer statements.
David: Yesterday there was a long discussion about icons for tense --- they seem to be generalized well beyond info-str.
oe: If we set things up so that when there's nothing to say we're forced to say there's nothing to say, at the very least it'll make our representations that much more unreadable.
Emily: The reasons have to do with composition…
oe: Sometimes I take the position that I don't care about composition and we should just talk about appropriate output representations, but maybe this isn't the right place for that.
Emily: How about a post-processing step that removes all uninformative info-str ICONS.
oe: That has the potential of making everything more complicated, possibly breaks (or undermines) reversability.
oe: So far it looks like what you're doing is equivalent to putting binary relations in the RELS list that are forced to have GTOP as their label. I thought part of the point of ICONS was to be able to allow new kinds of underpsecification for example absence.
Sanghoun: Original idea of ICONS had to do with binding constraints.
Kim loves kimself. x1 e2 x3 x1 eq x3 Kim loves kim. x1 e2 x3 x1 neq x3
oe: Why do we need the neq there?
Emily: Binding theory --- this is all we can say.
oe: But doesn't different variables already say that?
Emily: Kim thinks Sandy loves kim
oe: Could use eq and possibly eq and a default assumption that when we say nothing then they cannot be equated.
Emily: But that's much more work than just putting in eq and neq when the grammar says so.
oe: Now you're using arguments about compositionality to design the semantic representations.
Emily: I believe that that's what this sessions about.
Francis: Only within sentences then? I'd hate to have to put in the 'possibly equivalent' statements across a whole discourse.
Francis: Segueway: For unexpressed arguments, there would be some people (e.g., Fillmore) who have classified them into different classes… definite null instantiation, indefinite null instantation.
Emily: That's info status
oe: Same as cognitive status?
Sanghoun: Want to talk about unexpressed arguments because they have the constraint that they can't be focused.
oe: Can we go back to the examples and add the example of topicalization in English:
(i) Kim likes cookies.
(ii) Cookies, Kim likes.
What do we say about cookies in (i)? That it's non-focused.
Sanghoun: Current idea is that focus_d should be replaced by the focus-or-topic info-str type.
oe: That sounds attractive because the _d_rel eps are no good, and don't give us the underspecification we want. focus-or-topic ICONS element: thumbs up. But now in Kim likes cookies, what do you say?
Sanghoun: It's underspecified, just info-str.
Emily: Purpose of the _d_rels is to allow an underspecified representation (? not sure how underspecification works here --EMB) so that from one representation, both topicalized and non-topicalized variants can be produced, but also exactly one of those can be requested via the input MRS.
Emily: We can almost do that: Kim likes cookies is underspecified, Cookies, Kim likes. has info-str constraints. Can be sure not to get Cookies, Kim likes but as far as I can see right now Kim likes cookies will always come out.
Sanghoun: [quick description of pitch accents] but this is hard because we don't have acoustics.
Emily: And in fact if the input is originally text, there was never any acoustics, but we could in principle tag ahead of time and then use that info.
oe: Somewhat akin to what we're doing with markup.
Emily: how did underspecification work with d_rels?
oe: It doesn't --- don't emulate those. It was back in the message days. The messages had pseudo ‘roles’ for topic and passive argument --- could leave those underspecified, but also say which we want or that we want neither (with anti-variable).
Emily/oe: MRS = Meaning Representation System (not just semantics, including other information that has a bearing on meaning)
oe/David: RELS = the propositional content, ICONS are a hammer a mechanism to adorn that.
oe: We've currently lost the ability to parse an active and get back an active and passive, and would like to get that back.
Emily: I think we solve the most important part of the problem right now -- allow underspecification, but able to block the topicalized ones. Maybe it's not wrong to always output SVO
oe/Francis: Would you take home encouragement to solve the whole problem?
David: How is active/passive part of the meaning?
Emily: It's not part of the truth-conditional semantics (unless you look at the interaction of scope preferences and voice, but that is separable), but it is certainly related to the presentation of the information, and that's related to what we're doing with info-str.
Emily/Sanghoun: But the relationship between passive and info-str is not a hard constraint.
oe: So perhaps information structure is not the right level of representation for the control we are hoping to achieve.
Emily: My intuition is that the right way to do this in the big picture is to give the realization ranker information from which it can learn that topics tend to be subjects and then choose passive when the promoted argument is known to be a topic. It doesn't seem right to micromanage the output of the generator on this point.
oe: But we often have the desire to do just that. Don't we Francis?
Francis: What's that? [explanation] My first reaction was yes, give me control. But maybe we don't need to be able to micromanage that. THinking purely practically, for some of the interface-y things that I'd like to see the grammars used for now, I can see some scenarios where you'd want to e.g., never use passive.
Emily: Then you can turn off passive in the grammar for generation…
Francis: For translation my default I want to be able to say active is active, but in real life I don't. It's sometimes the case that things will be … hmmm… Occasionally we have transfer rules in the current system where something that's active in source should come out as active, but also some specific rules that take active in one language (for some specific lexicalization? -EMB)
oe: Passive has some function, it's a deliberate choice often. In two languages where they are used in a similar way, in a translation system it would be useful to be able to make sure they are the same in source and target.
David: Shouldn't you be translating the function, not the structure?
Emily: Just because we want to make this general enough to get something out of info-str marking in Japanese in JaEn doesn't mean we should necessarily make it harder in e.g. German <> English translation.
Emily: There are constructions in English whose sole purpose is to mark info-str, but passive isn't one of them.
oe: When all that the grammar tells us is info-str, …. I worry that our meaning representations will become unwieldy if we spell out those info-str relations for each instantiated or uninstantiated semantic role.
Francis: and that feeling I share very strongly.
Emily: Suggestions for what to do?
oe: Injection of non-vanilla statements into ICONS can maybe happen later (when they are specialized to something interesting)?
Emily: Can't have every construction/lex rule/lex item that gives us some information do the moving to the ICONS list, because then we might get double copies.
oe: So the suggestion is to find some mechanism…
Emily: Sanghoun, can you remind me why the selecting heads are introducing the underspecified ICONS, rather than the over lexical items?
oe: Don't elements have info-str with respect to all clauses they are in?
Emily: For a while at least we were maintaining that it is only the clause in which they are overt:
Kim tries to sleep x1 e2 e3 e2 info-str x1 e2 info-str e3 e2 info-str e2
Emily: And in relative clauses we have the relative pronoun or relative clause rule serves to gives us another overt point.
Francis: Why e2 info-str e2?
A: Did Kim sleep?
B: Kim TRIED to sleep.
oe: message slippery slope …
Emily: Optimistically sketching an analysis where CLAUSE-KEY an analysis where elements down inside modifiers and non-finite VPs have info-str with respect to the matrix clause, including in cases like:
Kim tried to hire SANDY
Hiring SANDY was difficult
The *IBM* report was late.
David: what about "The IBM report" --- no clause.
oe: Actually, in the semantics we have an unknown_v rel.
Emily: One further potential argument for the underspecified info-str ICONS elements cluttering things up is supporting an analysis of focus projection.
oe: One could also argue that they should be introduced as they are needed.