Deception detection in dialogues

In the social media era, it is commonplace to engage in written conversations. People sometimes even form connections across large distances, in writing. However, human communication is in large part non-verbal. This means it is now easier for people to hide their harmful intentions. At the same time, people can now get in touch with more people than ever before. This puts vulnerable groups at higher risk for malevolent interactions, such as bullying, trolling, or predatory behavior. Furthermore, such growing behaviors have most recently led to waves of fake news and a growing industry of deceit creators and deceit detectors. There is now an urgent need for both theory that explains deception and applications that automatically detect deception. In this thesis I address this need with a novel application that learns from examples and detects deception reliably in natural-language dialogues. I formally define the problem of deception detection and identify several domains where it is useful. I introduce and evaluate new psycholinguistic features of deception in written dialogues for two datasets. My results shed light on the connection between language, deception, and perception. They also underline the challenges and difficulty of assessing perceptions from written text. To automatically learn to detect deception I first introduce an expressive logical model and then present a probabilistic model that simplifies the first and is learnable from labeled examples. I introduce a belief-over-belief formalization, based on Kripke semantics and situation calculus. I use an observation model to describe how utterances are produced from the nested beliefs and intentions. This allows me to easily make inferences about these beliefs and intentions given utterances, without needing to explicitly represent perlocutions. The agents’ belief states are filtered with the observed utterances, resulting in an updated Kripke structure. I then translate my formalization to a practical system that can learn from a small dataset and is able to perform well using very little structural background knowledge in the form of a relational dynamic Bayesian network structure

To Tell The Truth: Language of Deception and Language Models

Text-based misinformation permeates online discourses, yet evidence of people's ability to discern truth from such deceptive textual content is scarce. We analyze a novel TV game show data where conversations in a high-stake environment between individuals with conflicting objectives result in lies. We investigate the manifestation of potentially verifiable language cues of deception in the presence of objective truth, a distinguishing feature absent in previous text-based deception datasets. We show that there exists a class of detectors (algorithms) that have similar truth detection performance compared to human subjects, even when the former accesses only the language cues while the latter engages in conversations with complete access to all potential sources of cues (language and audio-visual). Our model, built on a large language model, employs a bottleneck framework to learn discernible cues to determine truth, an act of reasoning in which human subjects often perform poorly, even with incentives. Our model detects novel but accurate language cues in many cases where humans failed to detect deception, opening up the possibility of humans collaborating with algorithms and ameliorating their ability to detect the truth

1956 és 1989 között keletkezett propagandaszövegek nyelvi sajátságai

Elemzésünkben a Magyar Szocialista Munkáspárt Központi Bizottságának (MSZMP KB) hivatalos havi lapja, a Pártélet els® és utolsó két évének lapszámait vizsgáljuk, és összehasonlítjuk a két id®szak szövegeinek statisztikai, morfológiai, szintaktikai és szemantikai jellemz®it. A vizsgált szövegek bizonyosan a totalitárius nyelvhasználatot reprezentálják, ezért kutatási eredményeinket felhasználhatónak tekintjük a politikai propaganda azonosítására és elemzésére irányuló kutatásokban és fejlesztésekben

Reading Mélusine : romance manuscripts and their audiences c.1380-c.1530

This thesis explores the historical reception of the prose Roman de Melusine and the poetic Roman de Parthenay from the twin perspectives of the romance manuscripts and their audiences. The Melusine romances attained wide popularity in manuscript form from their composition in the late fourteenth century until the early sixteenth century. By investigating the patronage, presentation, and ownership of the romance manuscripts, I ask how and why the works appealed to and retained their hold on later medieval imaginations? What cultural values did the romances express or reflect and what meanings did they attain which might have facilitated their circulation far beyond the boundaries of Poitou? In exploring these questions, my study offers a nuanced historical appraisal of the place of the Melusine romances in the cultural lives of late medieval Francophone audiences. The Melusine romances are located in over thirty surviving manuscripts. Employing an interdisciplinary approach, my research analyses the relationships between the themes expressed in these manuscripts, and the historical concerns of the French and Flemish nobility who constituted the romances’ primary audience. In addition to exploring and revising conventional explanations for the patronage of the romances, I examine the textual, paratextual, and decorative mouvance to which the romances were subject, and the intertextual relationships created by the inclusion of the romances within compilation manuscripts. From this analysis, I identify a series of themes which demonstrably intersected with the interests and anxieties of noble reading communities among whom the manuscripts circulated. This thesis thus complements and extends existing studies of manuscript decoration and the historical reception of early editions of the prose Melusine romance which were enjoyed by a cross-section of social groups from the 1470s onwards. My research suggests that the Melusine romances attained a significant position in late medieval noble culture for two interrelated reasons. First, the medium of the manuscript itself offered a flexible format which accommodated the changing preferences of patrons and audiences of the romances. Second, and paradoxically, Melusine manuscripts persistently expressed a range of concepts and attitudes of enduring relevance to their noble audiences with respect to: issues of dynastic prestige and the legitimacy of territorial tenure; metaphysical and spiritual concerns about fate and salvation; political propaganda; government; and education. The value of my study lies in the insights it offers into the mentalites of the later medieval nobility, a numerically small but influential social group, and the relationships between elite audiences and their preferred forms of literate culture. This thesis extends scholarly understandings of, and offers fresh hypotheses for the patronage of the Roman de Melusine and the Roman de Parthenay respectively. Further, it contextualises its analysis of the Melusine manuscripts and compilation contents in the light of historical events and concerns confronting late medieval noble audiences. It thus demonstrates the importance of combining literary and historical approaches when exploring the values and meanings attached to historical literature. While historical and literary approaches each offer unique insights into medieval understandings of a work, it is only by contextualising each set of findings produced by the two modes of analysis against each other that a nuanced appreciation of a literary work’s historical role and importance can be produced