Every now and then the world works exactly the way our best reasoning (and theory) says it is supposed to work. Pauli (whose proposal was en-theoried by Fermi) postulates the neutrino to save the laws of conservation and momentum in the face of troubling data from beta decay (see here) and 20 years later the little rascalino is detected and 40 years later Nobel prizes are collected. Ditto for the Higgs field, but this time the lag was over 40 years from theory to detection, and again a Nobel for the effort. These are considered some of the great moments in science for they are times when theory insisted that the world was a certain way despite apparent counter-evidence, and patience plus experimental ingenuity proved theory right. In other words, we love these cases for they comes as close as we can hope to get to having proof that we understand something about the world.
Now linguistics (I am almost embarrassed to say this, but I really don’t want to be painted as hyperbolic) is not quantum mechanics. It’s not even Newtonian mechanics (if only!). But every now and then we can snag a glimpse of FL by considering how its theories, and the logic that allows us to develop these, yield unexpected validation of its core tenets. The logic I refer to in this case is the PoS. Many denigrate its value. Many are suspicious of its claims and dispirited by its crude reasoning. They are wrong. Today I want to point to one of its big success stories. And I want to luxuriate in the details so that the wonders of PoS thinking shine clearly through.
The Athens participants, to a person, touted islands effects as one of GG’s great discoveries. It is such for several reasons.
First, they are non-obvious in the simple sense that the fact that islands exist is not cullable from inspection of live text. Listen all you want to the speech around you and you will nary spot an island. It is the classic example of a dog that doesn’t bark. It is only when you ask informants about extractions that the distinctive properties of structures as islands shines through.
Second, it takes quite a bit of technical apparatus to even describe an island. No conception of phrasal structure, no islands. No understanding of movement as a transformation of a certain sort, no islands. So, the very fact that islands are linguistic objects with their own distinctive properties only becomes evident when the methods and tools of GG become available.
Third, and IMO the most important point, islands are perfect probes into the structure of FL and were among the first linguistic objects to tell us anything about its structure. Why are they perfect probes? Because if islands exist (and they do, they do) then their existence must be grounded in the structure of FL. Let me say this very important point another way: the fact that there are islands cannot be something that is learned (in the simple sense learning as induction from the ambient linguistic data). That islands exist and constrain movement operations cannot possibly be learned because there is no data to learn this from in the PLD. Indeed, absent inquiries by pesky linguists interested in islands, there would be virtually no data at all concerning their islandish properties, neither in the PLD nor the positive LD. Island data must be manufactured by hard working linguists to be seeable at all. Thus, island phenomena are the quintessential examples of linguists acting like real scientists: they are unobvious, based on factitious data, only describable against a pretty sophisticated technical background and pregnant with implication for the fine structure of the principle object of inquiry, FL. Wow!! So islands are a really, really, really big deal.
And this sets up why this poster by Dave Kush, Terje Lohndal and Jon Sprouse (KLS) is so exciting. As the third point above notes, what makes islands so exciting is that they are the perfect probes into the structure of FL precisely because whatever properties they have cannot possibly be learned and so must reflect the native structure of FL. To repeat, there exists no data relevant to identifying islands and their properties in either the PLD or the positive LD. But this absence of data implies that island effects should not vary across Gs. Why? Because variation is a function of FL’s response to differential data input and if there is no plausible data input relevant to islands then there cannot be variation. However, for many years now, it has been argued that different Gs invidiously distinguish among the islands. In particular, since the early 1980s several have argued that the Scandinavian languages don’t have islands. KLS shows that this is simply incorrect. Here’s how it shows this.
The argument that Scandinavian Gs are not subject to islands rests on the claim that they do not display island effects. What are island effects? These are the native speaker judgments which categorize extractions out of islands as unacceptable. Thus, a native speaker of English will typically judge (1) as garbage, this being typically annotated with a “*”.
(1) *What did the nominee hear the rumor that Jon got
In contrast to this judgment concerning (1) in English, the claim has been that speakers of Swedish and Norwegian accept such sentences and do not give them *s. Maybe they give them at most a ?, but never a *. So the basis for the claim that Scandinavian Gs are exempt from islands is that native speakers do not find them unacceptable. The conclusion that has been drawn is that Gs vary wrt to islands. But this is impossible given PoS reasoning that implies that Gs could never so vary, ever. As you can see, there is an impasse here: theory says no variation, empirics say there is. Not surprisingly, given the low value much of the field assigns to PoS style theoretical “speculation” (aka logic), much of the field has concluded that there is something deeply wrong about our theory of islands. 
Now for a long time this is how things sat. The obvious answer to this empirical challenge is to deny that Scandinavian acceptability judgments are good indicators of grammaticality wrt Scandinavian islands. In other words, the fact that Scandinavian speakers accept movement out of Scandinavian islands does not imply that the structures so derived are grammatical. More pithily, in this particular case (un)acceptability poorly tracks (un)grammaticality.
Let me quickly say two things about this general point before proceeding lest too big a moral gets drawn. First, it is important to remember that within GG, conceptually speaking, “ungrammatical” is not a synonym for “unacceptable,” despite the practice within linguistics of confusing them (especially terminologically). “Acceptable” is a descriptive predicate of data points, a report of speaker judgments. “Grammatical” is a theoretical predicate applied to G constructs. GGers have been lucky in that over a large domain of data the two notions coincide. In other words, often, (un)acceptability is a good indicator of (un)grammaticality. However, one obvious way of dissolving the Scandinavian counter-examples above is to suggest that the link between the two is looser in this particular case. In other words, that the English data is more revealing of the underlying G facts than is the Scandinavian data in this case.
Second, the fact that this may be so in this case does NOT mean that acceptability is always or generally or usually a bad indicator of grammaticality. It isn’t. First, as Sprouse and Almeida and Schutze have demonstrated in their various papers, over a large and impressive range of data, the quick and dirty acceptability judgment data is a very stable and reliable kind of data. Second, cross-linguistic research over the last 60 years has shown that the MLGs discovered in one language using acceptability data in that language generally map quite well onto the acceptability data gathered in other languages for the same constructions. In fact, what made the Scandinavian data intriguing is that it was somewhat of an outlier. Many many languages (most?) exhibit English style island effects. So, even if the assumption that acceptability tracks grammaticality might not be perfectly correct, it is roughly so and thus it is prima facie reasonable to take it to be a faithful indicator of grammaticality ceteris paribus.
Ok, back to KLS. How does it redeem the PoS view of islands? Well, it provides a method for detecting island effects independently of binary (i.e. ok vs *) acceptability judgments. The probe comes from a battery of relative acceptability data gathered using the now well-known techniques of Experimental Syntax (ES). ES does acceptability judgment gathering more carefully than we tend to do. Factors are separated out (distance vs island) and their interaction (more) carefully compared. Using this technique one can gather relative acceptability data even among sentences all of which are judged quite acceptable. Using this method, the empirical signature of ungrammaticality is a super additivity (SA) profile apparent when you cross distance and structure.
With this machinery in place, we are ready for KLS’s big find. KLS applies this SA probe to English and Scandinavian and shows that both languages display a SA profile for sentences involving extraction from islands. Where the languages differ then is not in being responsive to islands but in how speakers map an island violation into a binary good/bad judgment. English speakers judge island violations as bad and Scandinavian speakers often judge them as ok.
Conclusion: Scandinavian obeys islands restrictions and this is visible when we use a more sensitive measure of G structure than ok vs *. In other words we clearly see the effects of islands in Scandinavian when we look at their SA profiles.
We should all rejoice here. This is great. The PoS reasoning we outlined above is vindicated. Gs do not differ wrt their obeisance to island restrictions and these are still excellent probes into the structure of FL. I, of course, am not at all surprised. The logic behind the PoS is impeccable. I have the irrational belief that if something is logically impossible then it is also metaphysically impossible. Thus, if some G difference cannot be learned due to an absence of any possibly relevant data, all Gs must be the same. This is as close to apodictic reasoning as we are likely to find in the non-mathematical sciences, so I have always assumed that the KLS results (or some other indication that Scandinavian obeys islands) must exist. That said, who can’t delight when logic proves efficacious? I know I can’t!
However, KLS is actually even more interesting than this. It not only vindicates the logic of the GG program against a long-standing apparent problem, but it also reshapes the domain of inquiry. How? Well, note that English and Scandinavian still differ despite the fact that both show island effects. After all, the former assign *s to sentences that the latter assign at most ?s to. Why? What’s going on? KLS offers some speculations worth investigating regarding how non-syntactic conditions might affect overall (i.e. binary) acceptability judgments. I personally suspect that this overall measure is affected by many different factors including intonation (and hence old/new info structure) lexical differentiation and a host of other things that I really can’t imagine. Sorting this out will be hard if for no other reason that we have not really concentrated much on how these myriad effects interact to provide an overall judgment. What KLS shows is that if we are interested in how speakers construct an overall judgment (and, off hand, it is not clear to me that we should be interested in this but I am happy to hear arguments for why we would be), then this is where you need to look for “variation.” Why? Because they have provided very good evidence that islands are NOT parameterized, which is the conclusion that elementary PoS reasoning leads to.
Diogo Almeida, has a nice paper (here, and here) that does similar things along these ES lines for extraction out of Wh-islands in Brazilian Portuguese (BP). The paper uses ES methods to probe not only sensitivity to islands but also to compare how sensitive different constructions are to island restrictions. The paper compares Topicalization and Left Dislocation showing that both induce island effects (as On WH Movement would lead us to expect). It also shows that BP here differs in part from English, raising further interesting research issues. I for one would love to see ES applied in comparing Topicalization, Left Dislocation and Hanging Topics in languages where one finds case connectivity effects. How do these do wrt islands? I can imagine a simple predication wherein case connectivity being a diagnostic of movement implies that Hanging Topics do not exhibit SA effects in island contexts. Is this so? I have no idea.
Diogo’s paper provides one further service. It provides a nice name for SA-without-unacceptability effects. Diogo dubs them “subliminal islands.” Diogo argues that the simple existence of subliminal effects has interesting implications for how we understand SA effects. He argues, convincingly IMO, that we expect subliminal effects if grammaticality is one component of acceptability, not so much if we take a performance view of islands. The paper also has a nice discussion of the conceptual relation between acceptability and grammaticality that I recommend highly.
Ok, time to end. I have two concluding points.
First, IMO, this kind of work demonstrates that ES can tell us something that we didn’t know before. Heretofore, ES work has aimed to either re-establish prior results (Jon’s work was aimed at showing that island effects are real) or to defend the homeland against the barbarians (Jon & Co arguing that informal methods are more than good enough much of the time). Here, KLS and Diogo’s paper show that we can resolve old problems and learn new things using these methods. In particular, these papers show that ES methods can open up new questions even in well-understood domains. In particular, I believe that both papers show that ES has the potential to reinvigorate research into the grammatical structure of islands. I mention this because many syntacticians have been wary of ES, thinking that it would just make everyone’s cushy life harder. And though I generally agree, that ES methods do not displace the more informal ones we use, these papers demonstrate that they can have real value and we should not be afraid (or reluctant) of using them.
Second, go out and celebrate. Tell friends about this stuff. It’s science at its best. Yipee!
 The impression I have (even after Athens) is that such speculation is considered to be just this side of BS. At the very least it really plays (and can play) no serious role in our practice. I may be a tad over-sensitive here.
 The fact that such a crude method of data collection has proven to be so reliable and useful raises an interesting question IMO: why? Why should such a dumb method of gathering data work so well? I believe that this is a function of the modularity of FL and the fact that Gs play a prominent role in all aspects of linguistic performance. More exactly, how Gs are used affects performance but performance does not affect how Gs are structured. Thus Gs make an invariant and important contribution to each performance. This is why their effects can be so easily detected, even using crude methods. At any rate, whether this diagnosis is correct, the fact that such a crude probe has been so successful is worth trying to understand.
 Note that this implies that the challenges to the universality of islands based on Scandinavian data were reasonable, even if ultimately wrong.
 KLS discusses Wh islands, Noun complement islands, subject islands and adjunct islands. It does not address relative clauses. However, Dave Kush has told me that they have looked at these too and the results are as expected: Scandinavian shows the same SA profile for RCs as for all the others.
 There is a kind of judgment one often hears from linguists which this methodology questions. It’s “the sentence is not perfect but it is grammatical.” The ES methodology suggests that one treat this kind of judgment very gingerly for it might indicate the underlying effects of the relevant G distinction, not its absence, as is typically concluded. Note that the quoted judgment above runs together “acceptable” and “grammatical” in a not wholly coherent way. It relies on the assumption that informal judgments concerning degree of unacceptability is a reliable probe of the binary grammatical/ungrammatical distinction. In other words, it assumes that grammaticality is binary (which it may be, but who knows) and that the severity of an acceptability judgment can reliably indicate the grammatical status of a structure. This assumption is challenged in the KLS paper.
 Sprouse’s thesis already demonstrated how e.g. D-linking could affect overall acceptability (i.e. the binary judgment) without inducing an SA signature.
 Same paper but for formatting. Latter is published version for citation purposes.