This dissertation examines the predictability of user engagement on online social platforms by integrating theoretical perspectives from the literature on media and technology habits with principles of context-aware computing. It presents three studies, each targeting a different facet of technology-mediated communication, from social media use in general to more granular behaviors like active and passive use and instant messaging. The first chapter proposes a novel approach to the study of social media habits through predictive modeling of sequential smartphone user behaviors. Using longitudinal smartphone app log data, it examines the predictability of app engagement as a way to capture a critical yet previously neglected aspect of media and technology habits: their embeddedness in repetitive behavioral sequences. The study employs Long Short-Term Memory (LSTM) and transformer neural networks to demonstrate that social media use follows predictable patterns over time and that its predictability varies substantially across individuals. T he second chapter shifts focus to the potential of context-aware modeling as a holistic yet parsimonious and privacy-preserving approach to predicting user engagement on online social platforms. Analyzing over 100 million Snapchat sessions from nearly 80,000 users via deep LSTM neural networks, the study demonstrates the predictability of active and passive use based on past behavior and a notable improvement in predictive performance upon integrating momentary context information. Features related to connectivity status, location, temporal context, and weather were found to capture non-redundant variance in user engagement relative to features derived from histories of in-app behaviors. The findings are consistent with the idea of context-contingent, habit-driven patterns of active and passive use, highlighting the utility of contextualized representations of user behavior for predicting user engagement on online social platforms. The third chapter investigates the predictability of attentiveness and responsiveness in instant messaging on a large online social platform. Utilizing metadata from over 19 million messages, the study examines the predictive power of a wide range of predictor groups, including message attributes, user attributes, and momentary context, as well as historical communication patterns within ego networks and dyadic relationships. The findings echo the overarching theme that habitual behaviors and contextual factors shape user engagement. However, in this case, dyad-specific messaging histories account for the overwhelming share of explained variance, underlining the socially interdependent nature of user engagement in instant messaging. Collectively, the three studies presented in this dissertation make a theoretical contribution by establishing media and technology habits as a suitable framework for the study of user engagement and by introducing a novel perspective that emphasizes the repetitive, predictable, and context-dependent nature of media and technology habits. The research makes an important empirical contribution through the use of novel, large-scale, objective behavioral data, enhancing the ecological validity and real-world applicability of its findings. Methodologically, it pioneers the use of context-aware sequential machine learning techniques for the study of media and technology habits. The insights garnered from this research have the potential to inform the design of engaging and ethical online social platforms and mobile technologies, highlighting its practical implications for the billions of users navigating these digital environments on a daily basis.

Popularity of mobile devices along with the presence of ad hoc networks requiring no infrastructure has contributed to recent advances in the field of mobile computing in ad hoc networks. Mobile ad hoc networks have been mostly utilized in military environments. The recent advances in ad hoc network technology now introduce a new class of applications. In this thesis, we design, implement and analyze a multi-hop ad hoc messenger application using Pocket PCs and Microsoft .Net Compact Framework. Pocket PCs communicate wirelessly with each other using the IEEE 802.11b technology without the use of an infrastructure. The main protocol implemented in this application is based on Dynamic Source Routing (DSR), which consists of two important mechanisms, Route Discovery and Route Maintenance. We adopt DSR since DSR operates solely based on source routing and "on-demand" process, so each packet does not have to transmit any periodic advertisement packets or routing information. These characteristics are desirable for the ad hoc messenger application for which a conversation is source-initiated on-demand. To test our application easily, we have developed a testing strategy by which a mobility configuration file is pre-generated describing the mobility pattern of each node generated based on the random waypoint mobility model. A mobility configuration file thus defines topology changes at runtime and is used by all nodes to know whether they can communicate with others in a single-hop or multi-hops during an experimental run. We use five standard metrics to test the performance of the wireless ad hoc messenger application implemented based on DSR, namely, (1) average latency to find a new route, (2) average latency to deliver a data packet, (3) delivery ratio of data packets, (4) normalized control overhead, and (5) throughput. These metrics test the correctness and efficiency of the wireless ad hoc messenger application using the DSR protocol in an 802.11 ad hoc network that imposes limitations on bandwidth and resources of each mobile device. We test the effectiveness of certain design alternatives for implementing the ad hoc messenger application with these five metrics under various topology change conditions by manipulating the speed and pause-time parameters in the random waypoint model. The design alternatives evaluated include (1) Sliding Window Size (SWS) for end-to-end reliable communication control; (2) the use of per-hop acknowledgement packets (called receipt packets) deigned for rapid detection of route errors by intermediate nodes; and (3) the use of cache for path look-up during route discovery and maintenance. Our analysis results indicate that as the node speed increases, the system performance deteriorates because a higher node speed causes the network topology to change more frequently under the random waypoint mobility model, causing routes to be broken. On the other hand, as the pause time increases, the system performance improves due to a more stable network topology. For the design alternatives evaluated in our wireless ad hoc messenger, we discover that as SWS increases, the system performance also increases until it reaches an optimal SWS value that maximizes the performance due to a balance of a higher level of data parallelism introduced and a higher level of medium contention in 802.11 because of more packets being transmitted simultaneously as SWS increases. Beyond the optimal SWS, the system performance deteriorates as SWS increases because the heavy medium contention effect outweighs the benefit due to data parallelism. We also discover that the use of receipt packets is helpful in a rapidly changing network but is not beneficial in a stable network. There is a break-even point in the frequency of topology changes beyond which the use of receipt packets helps quickly detect route errors in a dynamic network and would improve the system performance. Lastly, the use of cache is rather harmful in a frequently changing network because stale information stored in the cache of a source node may adversely cause more route errors and generate a higher delay for the route discovery process. There exists a break-even point beyond which the use of cache is not beneficial. Our wireless ad hoc messenger application can be used in a real chatting setting allowing Pocket PC users to chat instantly in 802.11 environments. The design and development of the dynamic topology simulation tool to model movements of nodes and the automatic testing and data collection tool to facilitate input data selection and output data analysis using XML are also a major contribution. The experimental results obtained indicate that there exists an optimal operational setting in the use of SWS, receipt packets and cache, suggesting that the wireless ad hoc messenger should be implemented in an adaptive manner to fine-tune these design parameters based on the current network condition and performance data monitored to maximize the system performance. / Master of Science

Thesis (MBA (Business Management))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The mobile phone has not only changed the way the world works today, but also changed the direction the world is moving toward. The mobile phone changed the face of communication and enabled more people to reach more other people than ever before. The big four banks in South Africa represent 83.5 per cent of the total asset value of all banks in South Africa. Traditionally, banking customers (or potential customers) could be reached through the current 2 786 branches, 19 451 ATMs and potentially 4.59 million internet users. There are 47.9 million mobile phone subscribers in South Africa – increasing the number of potential contact points by order of magnitude. The possibilities for banks utilising the mobile phone are endless, however online banking and offering banking services through a mobile phone is increasingly more subject to fraud attacks. Online banking and credit card fraud is still on the increase. Today, SMS is used to alert customer of movements on their bank account. This keeps the customer informed and enables them to notify their banks and prevent subsequent fraudulent transactions. SMS can be sent from one mobile phone to another (P2P) or from a computer system to a mobile phone (A2P). In 2007, 2 trillion SMS's were sent worldwide and was responsible for 75 to 80 per cent of all mobile phone revenues. South Africa sent 34 billion A2P SMS in 2009 of which 29 per cent were sent as transactional SMS by the top three banks in South Africa. SMS-based transactional alerts are SMS sent each time a change occurs in a bank account, for example, when your credit card is used then you will get an SMS on your mobile phone. Each bank makes different functionalities available. Absa reported 2 million customers receiving SMS alerts in 2008. FNB reported 67 million transactional SMS per month in 2009. The core advantages for using transactional SMS are the cost, reliability and ubiquity. Research was conducted among five of the six largest banks. Data revealed that banks send between 16 million and 69.4 million SMS per month and have approximately between 4.5 and 5.1 million customers using this service. The impact was tested through personal interviews. The two common factors were fraud reduction and customer retention. The two key challenges the banks identified are: i) Capacity/throughput with the mobile network operators; and ii) Getting internal systems and processes defined and working together for the alerts. The advantages identified are competitive positioning, customer interaction, empowerment of people and revenue. Key findings of the research were: SMS-based transactional alerts offer strategic importance; Any system is as good as it is being utilised; Security controls are extremely complex; SMS capacity is a common challenge and big risk; Internal processes cause the most complexity; Return on investment is not adequately measured; Transactional alerts is a potential revenue stream; There is no interaction between the bank and the customer; SMS in South Africa create high dependencies; SMS-based transactional alerts are successful.

O imediatismo relacionado a troca de informações é uma realidade enfrentada pela população dos tempos modernos e o uso de sistemas de mensagens instantâneas móveis (MIM) é indispensável para que a comunicação aconteça da forma esperada. Atualmente a maioria da população mundial utiliza de sistemas MIM como meio de comunicação rápida e muitas vezes gratuita, com a finalidade de auxiliar a comunicação no ambiente de trabalho, troca de informações gerais e também como um meio de entretenimento. Devido a sua importância e eficácia é que diversas pesquisas buscam entender os fatores que determinam a adoção e o uso desses sistemas. Esta pesquisa tem como objetivo avaliar por meio da percepção de estudantes do ensino superior, os fatores que afetam o uso dos serviços de mensagens instantâneas móveis. Para alcançar este objetivo, foi realizada uma pesquisa survey com 1.386 estudantes de quatro instituições de ensino superior. Após a coleta foi realizada a modelagem das equações estruturais com o uso do software SmartPLS 2.0 para o cálculo dos mínimos quadrados parciais (Partial Least Squares - PLS), além do uso do Statistical Package for Social Sciences (SPSS) para a análise descritiva dos dados. Esta pesquisa obteve como resultado que o construto Qualidade do serviço influencia positivamente na Confirmação, bem como a Confirmação tem relação positiva com a Utilidade percebida, Prazer percebido, Interface do usuário e Segurança percebida. Prazer percebido e Interface do usuário tem relação positiva com a Satisfação e as relações entre Satisfação, Utilidade percebida e Prazer percebido influenciam positivamente na Intenção de continuidade de uso do sistema WhatsApp. Identificou-se que, no contexto desta pesquisa, o prazer e a satisfação atuam como fatores que influenciam diretamente na intenção de continuidade de uso do sistema WhatsApp, seguidos pela Utilidade, o que faz o uso deste sistema ser mais intuitivo do que prático. / Immediacy related to the exchange of information is a reality faced by the population of modern times and the use of mobile instant messaging (MIM) is indispensable for the communication to happen as expected. Today the majority of the world's population uses MIM systems as a fast and often free medium for the purpose of helping communication in the workplace, exchange of general information and also as a means of entertainment. Due to its importance and effectiveness, several studies seek to understand the factors that determine the adoption and use of these systems. This research aims to evaluate, through the perception of students of higher education, the factors that affect the use of mobile instant messaging services. To achieve this goal, a survey was conducted with 1,386 students from four higher education institutions. After the collection, the modeling of the structural equations was performed using the SmartPLS 2.0 software for the calculation of the partial least squares (PLS), besides the use of the Statistical Package for Social Sciences (SPSS) for the descriptive analysis of the data. This research has as a result that the Quality of Service construct positively influences Confirmation, as well as Confirmation has positive relation with Perceived Utility, Perceived Pleasure, User Interface and Perceived Security. Perceived pleasure and user interface has a positive relationship with satisfaction and the relationship between satisfaction, perceived utility and perceived enjoyment positively influences the intention to use the WhatsApp system. It was identified that, in the context of this research, pleasure and satisfaction act as factors that directly influence the intention to use WhatsApp system, followed by Utility, which makes the use of this system more intuitive than practical.

Submitted by Timbo Noeme (noeme.timbo@metodista.br) on 2016-08-09T17:10:01Z No. of bitstreams: 1 LeonardoMMuniz2.pdf: 1320890 bytes, checksum: e1d55ac3650fd4a9ee03b53c73b61a12 (MD5) / Made available in DSpace on 2016-08-09T17:10:01Z (GMT). No. of bitstreams: 1 LeonardoMMuniz2.pdf: 1320890 bytes, checksum: e1d55ac3650fd4a9ee03b53c73b61a12 (MD5) Previous issue date: 2015-12-15 / The internet is part of every people daily life and becomes increasingly accessible through different types of devices. Several studies have been conducted in order to assess the consequences of their excessive use in personal, academic and professional life. This paper aimed to identify if the concentration and social isolation are some of the reflections by the excessive use of instant messaging applications in the workplace. Some of the variables that assess aspects of excessive use of instant messaging are diminished impulse control, loneliness, social comfort, and digital distraction. Through a quantitative research approach, it was used scales applied to a sample of 283 people, the data was analyzed by multivariate techniques like Exploratory Factor Analysis and Multiple Linear Regression. The results of this study confirm that the excessive use of instant messaging is positive related to loss of concentration and the variable digital distraction exerts a greater influence than the diminished impulse control. However, according to the results, loneliness and social comfort cannot be said that there is a relationship in increasing social isolation due to lack of significance of the relationship. / A Internet está inserida no cotidiano do indivíduo, e torna-se cada vez mais acessível por meio de diferentes tipos de dispositivos. Com isto, diversos estudos foram realizados com o intuito de avaliar os reflexos do seu uso excessivo na vida pessoal, acadêmica e profissional. Esta dissertação buscou identificar se a perda de concentração e o isolamento social são alguns dos reflexos individuais que o uso pessoal e excessivo de aplicativos de comunicação instantânea podem resultar no ambiente de trabalho. Entre as variáveis selecionadas para avaliar os aspectos do uso excessivo de comunicadores instantâneos tem-se a distração digital, o controle reduzido de impulso, o conforto social e a solidão. Através de uma abordagem de investigação quantitativa, utilizaram-se escalas aplicadas a uma amostra de 283 pessoas. Os dados foram analisados por meio de técnicas estatísticas multivariadas como a Análise Fatorial Exploratória e para auferir a relação entre as variáveis, a Regressão Linear Múltipla. Os resultados deste estudo confirmam que o uso excessivo de comunicadores instantâneos está positivamente relacionado com a perda de concentração, e a variável distração digital exerce uma influência maior do que o controle reduzido de impulso. De acordo com os resultados, não se podem afirmar que a solidão e o conforto social exercem relações com aumento do isolamento social, devido à ausência do relacionamento entre os construtos.

Jag undersöker chattmeddelandet i forumet Facebook Messenger för att se om jag kan finna mönster i de språkliga egenskaper som återfinns. Jag undersöker om egenskaperna innehar mest talspråkliga eller mest skriftspråkliga egenskaper, alternativt om egenskaperna kan anses vara unika för internetchatt. Syftet är att betrakta om chattspråk kan anses vara en självständig varietet i svenska språket.   Materialet består av chattkonversationer från tio informanter födda på 1990-talet samt sju informanter födda på 1960-talet. Genom att söka språkliga mönster hos två olika åldersgrupper går det att belysa huruvida konventionella språkegenskaper i chatt kan vara en generationsfråga. Jag använder en kvantitativ innehållsanalys för att analysera mitt material då jag har valt att kvantifiera de chattspråksegenskaper som jag har funnit. Jag har kvalitativa inslag i min analys för att ha möjlighet att tolka mitt resultat.   Det går att finna mönster i informanternas chattspråk. Det är vanligt att informanter brukar två utropstecken på rad, ”!!”, när de vill betona något i sitt meddelande. Det är också vanligt att utelämna information från chattmeddelanden: framförallt subjektspronomen eller prepositioner.   Det finns skillnader åldersgrupperna emellan. De yngre informanterna brukar många emoticoner medan de äldre gör det vid enstaka tillfällen. De yngre informanterna brukar emoticoner som satsavdelare – i stället för punkt och kommatecken – medan de äldre skriver enligt mer formella skriftspråksnormer. De äldre informanterna skriver ofta inledningar och avslutningar på sina meddelanden vilket de yngre inte gör.   Chattspråk, eller internetspråk, kan sägas vara en självständig språkvarietet även om de flesta språkliga egenskaperna inte är genuint nya. Verksamheten för kommunikation styr språket. Syftet med var och varför människor skriver till varandra har förändrats på grund av internet, vilket påverkar språket.

In this thesis, I use a multi-perspectival analytical approach to investigate the paralanguage of naturally occurring work-based Instant Message conversations. My research into the field of computer-mediated discourse analysis (CMDA) has shown that written non-verbal cues have been considered as important means of contextualising text-based computer-mediated communication (CMC), yet their scholarly treatment has been scant. Previous findings about the importance paralanguage in CMD have been further strengthened by the findings of the field of business communication: in the virtual work environment the lack of audio-visual information has been found to contribute to miscommunication and consequently hinder cooperation. The linguistic devices and discursive strategies that are used in order to compensate for the limitations imposed by the text-based communicative channel have therefore been identified as in need of further exploration. In this thesis, I have outlined a CMC cue system based on the previous findings of CMDA to investigate the range of cues used as non-verbal signals in workplace text- based CMC. I have also used a multi-perspectival approach based on the theoretical frameworks of interactional sociolinguistics, communities of practice, relational work and politeness and conversation analysis (CA) in order to investigate the range of interactional roles of paralanguage during computer-mediated business conversations. The interpretive CA-informed analysis I have conducted has provided evidence of the important role of non-verbal signals during the contextualisation of complex transactional and relational communicative goals in the workplace. The analysis in this thesis has provided two significant results: firstly, by incorporating the findings of research into paralanguage of spoken as well as other written genres it resulted in a comprehensive description of the orthographic and typographic non-verbal cues used in text-based CMC and, secondly, by drawing on the multi-perspectival framework, it allowed for a description of the complex interactional functions of these cues during the contextualisation of content and relational intent and the creation of interactional coherence in IM.

Magister Scientiae - MSc / Text communication is often perceived as lacking some components of communication that are essential in sustaining interaction or conversation. This interaction incoherency tends to make text communication plastic. It is traditionally devoid of intonation, pitch, gesture, facial expression and visual or auditory cues. Nevertheless, Instant Messaging (IM), a form of text communication is on the upward uptake both on PCs and on mobile handhelds. There is a need to rubberise this plastic text messaging to improve co-presence for text communications thereby improving synchronous textual discussion, especially on handheld devices. One element of interaction is gesture, seen as a natural way of conversing. Attaining some level of interaction naturalism requires improving synchronous communication spontaneity, partly achieved by enhancing input mechanisms. To enhance input mechanisms for interactive text-based chat on mobile devices, there is a need to facilitate gesture input. Enhancement is achievable in a number of ways, such as input mechanism redesigning and input offering adaptation. This thesis explores affective gesture mode on interface redesign as an input offering adaptation. This is done without a major physical reconstruction of handheld devices. This thesis presents a text only IM system built on Session Initiation Protocol (SIP) and SIP for Instant Messaging and Presence Leveraging Extensions (SIMPLE). It was developed with a novel user-defined hotkey implemented as a one-click context menu to "fast-track" text-gestures and emoticons. A hybrid quantitative and qualitative approach was taken to enable data triangulation. Results from experimental trials show that an Affective Gesture (AG) approach improved IM chat spontaneity/response. Feedback from the user trials affirms that AG hotkey improves chat responsiveness, thus enhancing chat spontaneity.

V této práci vytváříme jednoduchý systém pro rychlou textovou komunikaci (IM), který využívá technologii Near-Field Communication (NFC) ke zlepšení bezpečnosti a soukromí. V první části zkoumáme samotnou technologii NFC. Poté se věnujeme možnostem NFC v operačním systému Android pro chytrá mobilní zařízení a také existujícím aplikacím, které tyto možnosti využívají. Rovněž zkoumáme nejmodernější přístup k bezpečnému IM, zejména Signal Protocol a jeho open-source implementaci pro Android. Dále pak navrhujeme IM systém, který používá Signal Protocol pro šifrování zpráv a NFC pro výměnu kryptografického materiálu, aniž by vyžadoval použití telefonních čísel nebo důvěryhodnou třetí stranu. Nakonec předkládáme vzorovou implementaci klientské i serverové aplikace a zhodnocení vlastností tohoto systému z hlediska soukromí a bezpečí.

Autour d'une question fondamentale comme celle de la présence, nous mobilisons une littérature interdisciplinaire grâce à laquelle les contributions de l'anthropologie et de la géographie sociale, de la théorie du théâtre et du cinéma, des performance studies, de la psychanalyse et de la sociologie, sont articulées dans la perspective de la phénoménologie et des sciences de l'information et de la communication. Notre façon d'habiter le monde a changé : l'être-en-ligne se révèle alors comme étant la nouvelle condition existentielle. La connexion au réseau, le web, les applications, dans leur ensemble, disposent les choses et les personnes selon des relations opérationnelles de proximité spatio-temporelle. Notre espace est un espace performatif, car il se produit à partir de nos actions, nos postures et nos gestes, gestes photo-graphiques, éminemment réflexifs, qui créent la mise en scène numérique. En allant au-delà du modèle de « l'interface », cette mise en scène est devenue la spatialité de raccordement de tous nos espaces d'action. Nous identifions alors la performativité du direct et de l’enregistrement, la performativité de l’être en train de…, de l’attention présentielle et du « suspens gestuel », la performativité des algorithmes et des notifications, la performativité des emoji et de tout ce qui «fait visage»; et encore, la performativité des questions et des messages automatiques derrière lesquels parfois il y quelqu’un et d’autres fois il n’y a personne (comme lorsqu’on sonne à la porte dans une scène de La cantatrice chauve). A la lumière d'une analyse socio-sémiotique de la gestuelle numérique, des écrans, du graphisme propre aux réseaux sociaux et aux applications de messagerie instantanée tout comme des « protocoles de la vie quotidienne », nous décrivons la présence comme étant toujours l'effet d'une médiation. Cette médiation est, à la fois, disjonction et fiction, car elle se manifeste dans l'écart et dans la différence aussi bien que dans la fiction de l'hypermédiatété. Il y a de la présence, en somme, s'il y a du jeu, au sens spatiale de l'expression « il y a du jeu » mais aussi au sens fictionnel et ludique du jouer à.…. Comme le garçon du café décrit par Sartre, nous jouons, fictionnons et de-fictionnons le réel, en faisant « comme si » était vrai ce qui, par ailleurs, l'est vraiment. / Around the fundamental question of presence, I draw on interdisciplinary literature whose contributions from the fields of anthropology and social geography, theatre and cinema theory, performance studies, psychoanalysis and sociology are articulated from the perspective of phenomenology and information and communication sciences. Our way of inhabiting the world has changed: online-being is the new fundamental existential condition. Our space is a performative space, because it is produced through our actions, our gestures, eminently reflexive photographic gestures, which create our digital mise en scène. This space has become the space which links together all of our active and social spaces. Here, I single out live and recorded performativity, the performativity of do-ing, the performativity of algorithms and of questions, of emojis and of all that which “fait visage”. After a socio-semiotic analysis of digital gestures, screens, the graphics of social networks and presence protocols, I describe presence as always being a mediation effect. This mediation is at once disjunction and fiction, beacause it works as a difference and as the fiction of hypermediality. Presence exists where there is play (jeu) as in the french expression “il y a du jeu”, refering to space, and in its fictional sense of play-acting. As with Sartre's café waiter, we play act in order to create reality and consciousness through fiction.