Computers play an increasingly large part in childrens daily lives, yet most interface design research has focused on adult users. One area of research that has informed adult interface design is the Media Equation, which explains how people respond to media in a fundamentally social manner and how they treat computers as social actors in interactions. To date, it was unknown whether these findings apply to children as well. This thesis investigates the effects of the Media Equation on children in three specific areas: praise, team formation, and politeness. It also examines whether varying the form of the computer affects the Media Equation in any way and whether there are any gender differences in how children respond to the Media Equation. <p> Little evidence was found to support the existence of Media Equation effects on children. Children responded positively regardless of whether any Media Equation elements were incorporated into the interfaces. These results raise doubts on whether there is any added value to including Media Equation principles into the design of childrens interfaces. The results do, however, shed some light on children-computer interaction and lead to a set of guidelines for designers of childrens technology.

Computers play an increasingly large part in childrens daily lives, yet most interface design research has focused on adult users. One area of research that has informed adult interface design is the Media Equation, which explains how people respond to media in a fundamentally social manner and how they treat computers as social actors in interactions. To date, it was unknown whether these findings apply to children as well. This thesis investigates the effects of the Media Equation on children in three specific areas: praise, team formation, and politeness. It also examines whether varying the form of the computer affects the Media Equation in any way and whether there are any gender differences in how children respond to the Media Equation. <p> Little evidence was found to support the existence of Media Equation effects on children. Children responded positively regardless of whether any Media Equation elements were incorporated into the interfaces. These results raise doubts on whether there is any added value to including Media Equation principles into the design of childrens interfaces. The results do, however, shed some light on children-computer interaction and lead to a set of guidelines for designers of childrens technology.

Under paradigmet “Computers are Social Actors” (CASA) har beteende mellan människor och datorer studeras utifrån mänskliga sociala regler och normer. En studie från 2000-talet baserad på detta paradigm är Youngme Moons “Intimate Exchanges: Using Computers to Elicit Self-Disclosure from Consumers”. I ett experiment intervjuades deltagarna av en stationär dator för att visa att den sociala regel som behandlar känslig självexponering också existerar mellan människor och datorer. I samband med teknikens utveckling ställs frågor om huruvida de tidigare vetenskapliga upptäckterna kring datorer och människors sociala relationer går att applicera på nyare teknik. Vår studie genomfördes i avseende att replikera Moons studie men där vi istället bytte ut den stationära datorn mot en smarttelefon. Ett experiment genomfördes med 18 testdeltagare som blev indelade i en försöksgrupp och två kontrollgrupper. I övrigt var villkor och frågor de samma som i Moons experiment. Deltagarna svarade på 15 personliga frågor genom en smarttelefon med speciellt utvecklad programvara. Graden av känslig självexponering i deltagarnas svar studerades sedan genom att analysera dess längd och genom bedömning av 5 oberoende “bedömare”. Den aktuella studien uppvisar ett annat resultat än Moon och finner inget stöd för att den sociala regeln som behandlar känslig självexponering existerar mellan människor och smarttelefoner. / The human responses to communicating media were highly studied during the 1990s as a part of the “Computers are Social Actors” (CASA) paradigm. A paradigm where behaviour in the human-computer relationship is studied on the basis of human-human social norms. One study, deriving from this paradigm is Youngme Moons “Intimate Exchanges: Using Computers to Elicit Self-Disclosure from Consumers”. Through an experiment where participants are interviewed by a desktop computer, Moon shows that the social norm of intimate self-disclosure exists between humans and computers. As new technology is developed, questions are raised as to whether the earlier scientific discoveries in human-computer relationships can be applied to newer technologies. Our study intended to replicate Moon's study and replace the desktop computer with a smartphone. An experiment was conducted in which 18 test participants were divided into one experimental group and two control groups, given the same conditions and questions as the participants in Moon's experiment. The participants were interviewed in 15 intimate questions through specially developed software on a smartphone. The intimacy of the participants' responses was studied by analyzing their word length and by an assessment by 5 external judges. The study landed in a different result compared to Moon and finds no evidence that the social norm of intimate self-exposure exists between people and smartphones.

abstract: This dissertation study quantitatively measured the performance of 345 students who received public speaking instruction through an online platform presented in one of six experimental conditions in order to explore the ability of online lectures to replicate the characteristics of instructor presence and learner interaction traditionally associated with face-to-face public speaking courses. The study investigated the following research questions: RQ1: How does the visibility of an instructor in a public speaking video lesson affect students' perception of presence? RQ2: How does the visibility of an instructor in a public speaking video lesson affect student learning? RQ3: How do self-explanation (Constructive) and note-taking (Active) types of learning activities affect students' perception of presence compared to passive lessons when presented in a video lesson? RQ4: How do self-explanation (Constructive) and note-taking (Active) types of learning activities affect student learning compared to passive lessons when presented in a video lesson? Additionally, the study collected qualitative feedback from participants on their experience in order to improve understanding of how to effectively design lectures for public speaking courses. Results of the study were unable to statistically distinguish between students assigned to treatments that varied in both modality and level of activity. However, a significant finding of this study is that learning gains and students' perception of instructor presence were positive across all conditions. The lack of significant differences by treatment indicates that the design attributes at the center of the study may be unnecessary considerations for developing content for online learning. Consequently, the improved performance of participants regardless of their assigned treatment in this study identifies a limitation to the application of Media Equation Theory and the Interactive-Constructive-Active-Passive (ICAP) Framework for designing online learning content for public speaking students as well as identifies two key implications: 1) exposure to an online lesson can increase learning; and 2) exposure to an online lesson can serve as a cost-effective alternative for producing lessons in public speaking courses. / Dissertation/Thesis / Doctoral Dissertation Educational Technology 2014

Indiana University-Purdue University Indianapolis (IUPUI) / Just as physical appearance affects persuasion and compliance in human communication, it may also bias the processing of information from avatars, computer-animated characters, and other computer interfaces with faces. Although the most persuasive of these interfaces are often the most humanlike, they incur the greatest risk of falling into the uncanny valley, the loss of empathy associated with eerily human characters. The uncanny valley could delay the acceptance of humanlike interfaces in everyday roles. To determine the extent to which the uncanny valley affects persuasion, two experiments were conducted online with undergraduates from Indiana University. The first experiment (N = 426) presented an ethical dilemma followed by the advice of an authority figure. The authority was manipulated in three ways: depiction (recorded or animated), motion quality (smooth or jerky), and recommendation (disclose or refrain from disclosing sensitive information). Of these, only the recommendation changed opinion about the dilemma, even though the animated depiction was eerier than the human depiction. These results indicate that compliance with an authority persists even when using a realistic computer-animated double. The second experiment (N = 311) assigned one of two different dilemmas in professional ethics involving the fate of a humanlike character. In addition to the dilemma, there were three manipulations of the character’s human realism: depiction (animated human or humanoid robot), voice (recorded or synthesized), and motion quality (smooth or jerky). In one dilemma, decreasing depiction realism or increasing voice realism increased eeriness. In the other dilemma, increasing depiction realism decreased perceived competence. However, in both dilemmas realism had no significant effect on whether to punish the character. Instead, the willingness to punish was predicted in both dilemmas by narratively characterized trustworthiness. Together, the experiments demonstrate both direct and indirect effects of narratives on responses to humanlike interfaces. The effects of human realism are inconsistent across different interactions, and the effects of the uncanny valley may be suppressed through narrative characterization.

Cette thèse s'inscrit dans le domaine des probabilités et des statistiques, et plus précisément des matrices aléatoires. Dans la première partie, on étudie les grandes déviations de la mesure spectrale de matrices de covariance $XX^*$, où $X$ est une matrice aléatoire rectangulaire à coefficients i.i.d. ayant une queue de probabilité en $exp(-at^{alpha})$, $alpha in ]0,2[$. On établit un principe de grandes déviations analogue à celui de Bordenave et Caputo, de vitesse $n^{1+alpha/2}$ et de fonction de taux explicite faisant intervenir la convolution libre rectangulaire. La démonstration repose sur un résultat de quantification de la liberté asymptotique dans le modèle information-plus-bruit. La seconde partie de cette thèse est consacrée à l'étude du comportement en temps long de la solution de l'équation de Fokker-Planck libre en présence du potentiel quartique $V(x) = frac14 x^4 + frac{c}{2} x^2$ avec $c ge -2$. On montre que quand $t to +infty$, la solution $mu_t$ de cette équation aux dérivées partielles converge en distance de Wasserstein vers la mesure d'équilibre associée au potentiel $V$. Ce résultat fournit un premier exemple de convergence en temps long de la solution de l'équation des milieux granulaires en présence d'un potentiel non convexe et d'une interaction logarithmique. Sa démonstration utilise notamment des techniques de probabilités libres. / This thesis lies within the field of probability and statistics, and more precisely of random matrix theory. In the first part, we study the large deviations of the spectral measure of covariance matrices XX*, where X is a rectangular random matrix with i.i.d. coefficients having a probability tail like $exp(-at^{alpha})$, $alpha in (0,2)$. We establish a large deviation principle similar to Bordenave and Caputo's one, with speed $n^{1+alpha/2}$ and explicit rate function involving rectangular free convolution. The proof relies on a quantification result of asymptotic freeness in the information-plus-noise model. The second part of this thesis is devoted to the study of the long-time behaviour of the solution to free Fokker-Planck equation in the setting of the quartic potential $V(x) = frac14 x^4 + frac{c}{2} x^2$ with $c ge -2$. We prove that when $t to +infty$, the solution $mu_t$ to this partial differential equation converge in Wasserstein distance towards the equilibrium measure associated to the potential $V$. This result provides a first example of long-time convergence for the solution of granular media equation with a non-convex potential and a logarithmic interaction. Its proof involves in particular free probability techniques.

Ce mémoire de thèse est consacré à l’équation de Fokker-Planckpartial_ f=∆f+div(Ef).Il est subdivisé en deux parties :une partie linéaire et une partie non linéaire. Dans la partie linéaire on considère un champ de vecteur E(x) dépendant seulement de x. Cette partie est constituée des chapitres 3, 4 et 5. Dans le chapitre 3 on montre que l’opérateur linéaire Lf :=∆ f + div(E f ) est le générateur d’un semi-groupe fortement continu (SL(t))_{t≥0} dans tous les espaces L^p. On y établit également que le semi-groupe (SL(t))_{t≥0} est positif et ultracontractif. Dans le chapitre 4 nous montrons comment est qu’une décomposition adéquate de l’opérateur L permet d’établir certaines propriétés du semi-groupe (SL(t))_{t≥0} notamment sa bornitude. Le chapitre 5 est consacré à l’existence d’un état d’équilibre. De plus on y montre que cet état d’équi- libre est asymptotiquement stable. Dans la partie non linéaire on considère un champ de vecteur de la forme E(x,f) := x+nabla (a*f) ou a et f sont des fonctions assez régulières et * est l’opérateur de convolution. Cette parties est contituée des chapitre 6 et 7. Dans le chapitre 6 nous établissons que poura appartenant à W^{2,infini}_locl’équation de Fokker-Planck non linéaire admet une unique solution locale dans l’espace L^2_{K_alpha} (R^d). Dans le dernier chapitre nous montrons que le problème non linéaire admet une solution globale. De plus cette solution dépend continument des données. / This thesis is devoted to the Fokker-Planck équation partial_t f =∆f + div(E f).It is divided into two parts. The rst part deals with the linear problem. In this part we consider a vector E(x) depending only on x. It is composed of chapters 3, 4 and 5. In chapter 3 we prove that the linear operator Lf :=∆f + div(Ef ) is an in nitesimal generator of a strong continuous semigroup (SL(t))_{t≥0}. We establish also that (SL(t))_{t≥0} is positive and ultracontractive. In chapter 4 we show how an adequate decomposition of the linear operator L allows us to deduce interesting properties for the semigroup (SL(t))_{t≥0}. Indeed using this decomposition we prove that (SL(t))_{t≥0} is a bounded semigroup. In the last chapter of this part we establish that the linear Fokker-Planck admits a unique steady state. Moreover this stationary solution is asymptotically stable.In the nonlinear part we consider a vector eld of the form E(x, f ) := x +nabla (a *f ), where a and f are regular functions. It is composed of two chapters. In chapter 6 we establish that fora in W^{2,infini}_locthe nonlinear problem has a unique local solution in L^2_{K_alpha}(R^d); . To end this part we prove in chapter 7 that the nonlinear problem has a unique global solution in L^2_k(R^d). This solution depends continuously on the data.