Forty years of experimentation on class inclusion and its probabilistic relatives have led to inconsistent results and conclusions about human reasoning. Recent research on the conjunction "fallacy" recapitulates this history. In contrast to previous results, we found that a majority of participants adhere to class inclusion in the classic Linda problem. We outline a theoretical framework that attributes the contradictory results to differences in statistical sophistication and to differences in response mode-whether participants are asked for probability estimates or ranks-and propose (...) two precise cognitive algorithms for ranking probabilities. Our framework allows us to make novel predictions about when and why people adhere to class inclusion. Evidence obtained in several studies supports these predictions and demonstrates that the proposed ranking algorithms can account for about three-quarters of participants' inferences in the Linda problem. (shrink)

Because the conjunction pandq implies p, the value of a bet on pandq cannot exceed the value of a bet on p at the same stakes. We tested recognition of this principle in a betting paradigm that (a) discouraged misreading p as pandnotq, and (b) encouraged genuinely conjunctive reading of pandq. Frequent violations were nonetheless observed. The findings appear to discredit the idea that most people spontaneously integrate the logic of conjunction into their assessments of chance.

In the spring of 1978, one of the authors of this book was sitting in on a course in logic for linguists given by the other author. In attempting to present some of Montague's insights in an elementary way, the authors began dis cussions aimed towards the construction of a simple model-theoretical semantic apparatus which could be applied directly to a small English-like language and used to illustrate the methods of formal logical interpretation. In these discussions two points impressed themselves (...) on us. First, our task could be simplified by using boolean algebras and boolean homomorphisms in the models; and second, the boolean approach we were developing had much more widespread relevance to the logical structure of English than we first thought. During the summer and fall of 1978 we continued work on the system, proving the more fundamental theorems and outlining the way in which an intensional interpretation scheme could be developed which made use of the boolean approach. We presented our findings in a monograph which the UCLA Linguistics Department kindly published as part of their series called Occa sional Papers in Linguistics; one of the authors also presented the system at a colloquium held at the Winter Meeting of the Linguistic Society of America in December 1978. (shrink)

It is easy to construct pairs of sentences X, Y that lead many people to ascribe higher probability to the conjunction X-and-Y than to the conjuncts X, Y. Whether an error is thereby committed depends on reasoners’ interpretation of the expressions “probability” and “and.” We report two experiments designed to clarify the normative status of typical responses to conjunction problems. © 2004 Cognitive Science Society, Inc. All rights reserved.

It is easy to construct pairs of sentences X, Y that lead many people to ascribe higher probability to the conjunction X‐and‐Y than to the conjuncts X, Y. Whether an error is thereby committed depends on reasoners' interpretation of the expressions “probability” and “and.” We report two experiments designed to clarify the normative status of typical responses to conjunction problems.

A conversational implicature is an inference that consists in attributing to a speaker an implicit meaning that goes beyond the explicit linguistic meaning of an utterance. This paper experimentallyinvestigates scalar implicature, a paradigmatic case of implicature in which a speaker's use of a term like Some indicates that the speaker had reasons not to use a more informative one from the samescale, e.g. All; thus, Some implicates Not all. Pragmatic theorists like Grice would predict that a pragmatic interpretation is determined (...) only after its explicit, logical meaning is incorporated (e.g. whereSome means at least one). The present work aims to developmentally unpack this prediction by showing how younger, albeit competent, reasoners initially treat a relatively weak term logically beforebecoming aware of its pragmatic potential. Three experiments are presented. Experiment 1 presents a modal reasoning scenario offering an exhaustive set of conclusions; critical among these isparticipants' evaluation of a statement expressing Might be x when the context indicates that the stronger Must be x is true. The conversationally-infelicitous Might be x can be understood logically(e.g. as compatible with Must) or pragmatically (as exclusive to must). Results from five-, seven-, and nine-year-olds as well as adults revealed that a) seven-year-olds are the youngest to demonstratemodal competence overall and that; b) seven- and nine-year-olds treat the infelicitous Might logically significantly more often than adults do. Experiment 2 showed how training with the modal taskcan suspend the implicatures for adults. Experiment 3 provides converging evidence of the developmental pragmatic effect with the French existential quantifier Certains (Some). Whilelinguistically-sophisticated children (eight- and ten-year-olds olds) typically treat Certains as compatible with Tous (All), adults are equivocal. These results, which are consistent with unanticipatedfindings in classic developmental papers, reveal a consistent ordering in which representations of weak scalar terms tend to be treated logically by young competent participants and morepragmatically by older ones. This work is also relevant to the treatment of scalar implicatures in the reasoning literature. (shrink)

Psychologists' work on conversational pragmatics and judgment suggests a refreshing approach to charitable interpretation and theorizing. This charitable approach—what I call Gricean charity —recognizes the role of conversational assumptions and norms in subject-experimenter communication. In this paper, I outline the methodological lessons Gricean charity gleans from psychologists' work in conversational pragmatics. In particular, Gricean charity imposes specific evidential standards requiring that researchers collect empirical information about (1) the conditions of successful and unsuccessful communication for specific experimental contexts, and (2) the (...) conversational norms governing communication in experimental contexts. More generally, the Gricean turn in psychological research shifts focus from attributional to reflexive, situational explanations. Gricean charity does not primarily seek to rationalize subject responses. Rather, it imposes evidential requirements on psychological studies for the purpose of gaining a more accurate picture of the surprising and muddled ways in which we weigh evidence and draw. Key Words: Gricean charity • methodological rationalism • interpretation • principle of charity • cognitive psychology • conversational pragmatics • heuristics and biases • reflexive analysis. (shrink)

In this study I examine some uses of connectives, and in particular co-ordinate conjunction, from a critical discourse perspective; these uses, in my view, cannot find a satisfactory explanation within current frameworks. It is suggested that we need to identify a conceptual level at which connectives function as hypo-textual signals, activating systematic law-like conditional statements (IF-THEN), which form default specifications of consistent structured knowledge frames. I argue that an account of connectives at the conceptual level of their function that does (...) not take into consideration such tightly structured background schemata, representing both general knowledge and ideologies, cannot afford any generality. As a result, ¿deviant¿ or ¿subversive¿ uses of these connectives can neither be identified as such nor find an adequately general explication within existing accounts, whereas in the proposed framework such uses find a ready explanation of sufficient generality. This framework lies at the intersection of disciplines: Linguistic pragmatics (empirical pragmatics, critical discourse analysis), on the one hand, and cognitive science, on the other. Consequently, this proposal, too, can be regarded as a plea for crossing boundaries and joining forces. (shrink)

In this study I examine some uses of connectives, and in particular co-ordinate conjunction, from a critical discourse perspective; these uses, in my view, cannot find a satisfactory explanation within current frameworks. It is suggested that we need to identify a conceptual level at which connectives function as hypo-textual signals, activating systematic law-like conditional statements, which form default specifications of consistent structured knowledge frames. I argue that an account of connectives at the conceptual level of their function that does not (...) take into consideration such tightly structured background schemata, representing both general knowledge and ideologies, cannot afford any generality. As a result, ‘deviant’ or ‘subversive’ uses of these connectives can neither be identified as such nor find an adequately general explication within existing accounts, whereas in the proposed framework such uses find a ready explanation of sufficient generality. This framework lies at the intersection of disciplines: Linguistic pragmatics, on the one hand, and cognitive science, on the other. Consequently, this proposal, too, can be regarded as a plea for crossing boundaries and joining forces. (shrink)

The first of its kind to thoroughly cover language technology at all levels and with all modern technologies this book takes an empirical approach to the ...

Our book Relevance (Sperber and Wilson 1986) treats utterance interpretation as a two-phase process: a modular decoding phase is seen as providing input to a central inferential phase in which a linguistically encoded logical form is contextually enriched and used to construct a hypothesis about the speaker's informative intention. Relevance was mainly concerned with the inferential phase of comprehension: we had to answer Fodor's challenge that while decoding processes are quite well understood, inferential processes are not only not understood, but (...) perhaps not even understandable (see Fodor 1983). Here we will look more closely at the decoding phase and consider what types of information may be linguistically encoded, and how the borderline between decoding and inference can be drawn. It might be that all linguistically encoded information is cut to a single pattern: all truth conditions, say, or all instructions for use. However, there is a robust intuition that two basic types of meaning can be found. This intuition surfaces in a variety of distinctions: between describing and indicating, stating and showing, saying and conventionally implicating, or between truth-conditional and non-truth-conditional, conceptual and procedural, or representational and computational meaning. In the literature, justifications for these distinctions have been developed in both strictly linguistic and more broadly cognitive terms. The linguistic justification goes as follows (see for example Recanati 1987). Utterances express propositions; propositions have truth conditions; but the meaning of an utterance is not exhausted by its truth conditions, i.e. the truth conditions of the proposition expressed. An utterance not only expresses a proposition but is used to perform a variety of speech acts. It can.. (shrink)