UA Open Access Publishing Fund / Background Missing outcome data is a threat to the validity of treatment effect estimates in randomized controlled trials. We aimed to evaluate the extent, handling, and sensitivity analysis of missing data and intention-to-treat (ITT) analysis of randomized controlled trials (RCTs) in top tier medical journals, and compare our findings with previous reviews related to missing data and ITT in RCTs. Methods Review of RCTs published between July and December 2013 in the BMJ, JAMA, Lancet, and New England Journal of Medicine, excluding cluster randomized trials and trials whose primary outcome was survival. Results Of the 77 identified eligible articles, 73 (95%) reported some missing outcome data. The median percentage of participants with a missing outcome was 9% (range 0 – 70%). The most commonly used method to handle missing data in the primary analysis was complete case analysis (33, 45%), while 20 (27%) performed simple imputation, 15 (19%) used model based methods, and 6 (8%) used multiple imputation. 27 (35%) trials with missing data reported a sensitivity analysis. However, most did not alter the assumptions of missing data from the primary analysis. Reports of ITT or modified ITT were found in 52 (85%) trials, with 21 (40%) of them including all randomized participants. A comparison to a review of trials reported in 2001 showed that missing data rates and approaches are similar, but the use of the term ITT has increased, as has the report of sensitivity analysis. Conclusions Missing outcome data continues to be a common problem in RCTs. Definitions of the ITT approach remain inconsistent across trials. A large gap is apparent between statistical methods research related to missing data and use of these methods in application settings, including RCTs in top medical journals.

Das Wissen um die Zeitpunkte des Eintretens von Handlungseffekten und die Re¬präsentation dieser Zeitpunkte ist unerlässlich, um adäquat mit der Umwelt inter¬agieren zu können. Der Erwerb zeitlichen Wissens im Handlungskontext sowie Ein¬flüsse auf die Repräsentation von Zeitdauern im Handlungskontext sollen in dieser Arbeit untersucht werden. Die Experimente 1-3 untersuchen den Erwerb zeitlicher Relationen im Handlungs¬kontext. In den Experimenten 1 und 2 sagen in zwei Grup-pen entweder Aktionen oder sensorische Reize Zeitpunkt und Identität eines nach¬folgenden Ereignisses voraus, auf das reagiert werden muss. Die Dauer von Zeit¬intervallen wird besser erlernt, wenn eine Aktion sie vorhersagt, als wenn ein Reiz sie vorhersagt. Die Kovariation der Aktion/des Reizes mit dem Ereignis und die damit verbundene Kovariation des Zeit¬intervalls mit dem Ereignis beeinflusst eine Reaktion auf das Ereignis nur, wenn die Auf¬gabe eine Diskrimination des Ereignisses fordert. Experiment 3 zeigt, dass der Erwerb zeitlicher Relationen im Handlungskontext auch dann nach¬zuweisen ist, wenn die exakte motorische Reaktion unabhängig von sowohl Zeitintervall als auch Identität des Ereignisses ist. Die Experimente 4-7 explorieren die Wahr¬nehmung der Dauer von Zeit-intervallen im Handlungskontext. Konkret wird dabei die Einschätzung der Dauer von Aktions-Effekt-Intervallen und von Effekten betrachtet. Unter¬suchungen zur Repräsentation von Zeitpunkten im Handlungskontext haben gezeigt, dass Aktions- und Effektzeitpunkte näher beieinander wahrgenommen werden als sie tatsächlich sind. Bisher wurde nicht überprüft, ob dementsprechend auch die Dauer eines Aktions-Effekt-Intervalls kürzer eingeschätzt wird als sie ist. Diese Lücke soll in dieser Arbeit mit Hilfe einer psycho¬physischen Methode zur Einschätzung der Dauer von Zeitintervallen geschlossen werden. Tatsächlich wird die Dauer eines Aktions-Effekt-Intervalls kürzer eingeschätzt (Experiment 4-6). Allerdings tritt diese Unter¬schätzung gleichermaßen für Aktions-Effekt-Intervalle wie für Reaktions-Effekt-Inter¬valle auf (Experiment 4). Bei der Einschätzung von Zeitpunkten werden eine passive taktile Reizung und ein folgender Reiz weiter voneinander entfernt wahrgenommen als die Zeitpunkte einer Aktion und ihres Effekts. Die Einschätzung der Zeitdauer ist da¬gegen zwischen einer Aktion und ihrem Effekt länger als zwischen taktiler Reizung und einem Reiz (Experiment 5). Die Experimente 6a-d zeigen, dass für eine kürzere Ein¬schätzung des Aktions-Effekt-Intervalls das Auftreten eines intendierten Effekts nicht notwendig ist. Stattdessen ist das Auftreten eines kausal durch die Aktion ver¬ursachten unspezifischen Effekts hinreichend. Die wahrgenommene Dauer eines 400 ms dauernden Effekts hängt dagegen von der Kontingenz seines Auftretens ab (Experi¬ment 7b), nicht aber die eines 250 ms dauernden Effekts (Experiment 7a). Die Experi¬mente 8 und 9 untersuchen den Zusammenhang von Kausalitäts- und Zeitwahrnehmung. Experiment 8 zeigt, dass Abweichungen vom erlernten Effektzeit¬punkt sowohl bei häufig verzögerten Effekten als auch bei häufig unmittelbaren Effekten erkannt werden, sich jedoch die zeitliche Auflösung unterscheidet. Dabei werden Effekte im gleichen Ausmaß als kausal verursacht wahrgenommen, in dem der Effektzeitpunkt als „wie üblich“ wahrgenommen wird. Experiment 9 untersucht, ob eine Manipulation der ange¬nommenen Anzahl von Ursachen zweier kurz nach¬einander auf¬tretender Reize einerseits und die Verursachung dieser Reize durch eine Aktion vs. den Computer anderer¬seits dazu führt, dass sie eher als gleich¬zeitig wahr¬ge¬nom¬men werden. Während die Verursachung der Reize durch eine Aktion dazu führt, dass die Reize tendenziell wahr¬scheinlicher als gleichzeitig wahr¬genommen werden, lässt sich kein Einfluss durch die Manipulation der angenommenen Anzahl von Ursachen finden. Insgesamt zeigt sich, dass zeit¬liche Relationen im Handlungskontext besonders gut erlernt werden. Darüber hinaus wird mit einer psychophysischen Methode bestätigt, dass Zeitintervalle in Handlungskontexten kürzer eingeschätzt werden als in anderen Kontexten. Verschiedene Einflüsse auf die Einschätzung der Dauer von Zeitintervallen im Handlungskontext, insbesondere Kausalität, werden näher untersucht und diskutiert. / It is valuable to know the point in time an action effect will occur and the representation of this point in time can be essential for adequate interaction with the environment. The acquisition of temporal knowledge in the action contexts as well as the representation of durations action contexts are examined in this thesis. Experiments 1-3 investigate the acquisition of temporal relations. In Experiments 1 and 2 in two groups either actions or sensory stimuli predict both the identity of ensuing events and the time intervals after which they occur. Participants’ task is to react to the event as quickly as possible. The duration of the time intervals is acquired better when they are predicted by actions than when they are predicted by sensory stimuli. The covariation of either actions or stimuli with the identity of ensuing events as well as the resulting covariation of the time intervals with the the identity of the events influence reactions to the event only when the task requires a discrimination of the event. Experiment 3 shows that temporal relations in action contexts are also acquired when the required motor response cannot be predicted by either time interval or the identity of the event. Experiments 4-7 explore how the duration of time intervals is perceived in action contexts. In particular, the estimated duration of action-effect intervals is observed. Studies on the representation of points in time in action contexts have shown that the points in time of actions and their effects are perceived to be closer together in time than they really are. It has not been studied yet if correspondingly the duration of action-effect intervals is perceived to be shorter as it really is. This is accomplished in this thesis by means of a psychophysical method used to gain estimations of perceived temporal durations. In fact, the duration of an action-effect interval is estimated to be shorter (Experiments 4-6). However, this underestimation occurs for reaction-effect intervals as well as for action-effect intervals (Experiment 4). Regarding the perception of points in time a passive tactile stimulation and an ensuing stimulus are perceived to be further apart from each other than the points in time of an action and its effect. However, the perceived duration between an action and its effect is longer than between a tactile stimulus and another stimulus (Experiment 5). Experiments 6a-d show that for the shortening of the perceived duration of an action-effect interval the appearance of the specific, intended effect is not necessary, but the appearance of a non-specific effect caused by the action is sufficient. In contrast, the perceived duration of effects lasting 400 ms depends on the contingency of its occurrence (Experiment 7b). However, this does not hold true for effects lasting 250 ms (Experiment 7a). Experiments 8 and 9 study the relationship of time perception and causality perception. Experiment 8 shows that deviations from the usual point in time of an effect’s occurrence are detected both if the effect usually occurs immediately after the action and if it usually occurs after a delay of 250 ms, but the temporal resolution differs between the two conditions. Moreover effects are perceived as having been caused by the action to the same degree as the point in time of their appearance is perceived to be “the same as usual”. Experiment 9 examines if the extent to which two stimuli appearing shortly after one another are perceived to have occurred simultaneously is influenced on the one hand by a manipulation of the perceived number of causes of those stimuli and on the other hand by the causation of those stimuli by either the participant’s action or the computer. Whereas stimuli caused by an action tend to be judged to have occurred simultaneously more often, no influence of the manipulation of the number of causes on the simultaneity judgment can be found. All in all, it is shown that temporal relations are acquired especially well in action contexts. Furthermore it is shown by means of a psychophysical method that time intervals are estimated to be shorter in action contexts. Different influences on duration estimations in the context of actions, i.e. causality, are examined in more detail and discussed.

Le bouche à oreille électronique s’est fortement développé ces dernières années surtout avec la multiplication de plateformes en ligne comme les réseaux sociaux. Traitant du cas des caractéristiques des messages en ligne (la force et de l’argumentaire des messages), ce travail nous a permis dans une première étape exploratoire de se familiariser avec le langage des internautes pour créer nos propres scénarios, de connaitre les principales interrogations des internautes concernant la crédibilité, la confiance et l’utilité de ces messages. Cette recherche et la revue de la littérature nous ont ainsi aidé à proposer un modèle conceptuel pivotant autour des caractéristiques des messages de bouche-à-oreille en ligne et leurs influences sur le comportement du consommateur.Une deuxième étape confirmatoire nous a permis de tester et de valider le modèle proposé etde vérifier ou d’infirmer certaines des hypothèses supposées. Les résultats statistiques montrent que les types des messages influencent la crédibilité perçue, l’intention d’achat et de recommandation. Les variables modératrices liées aux caractéristiques du récepteur des messages modèrent ces relations. Des variables médiatrices (i.e. la confiance perçue et l’utilité perçue des messages) sont considérées comme fondamentales pour l’évaluation des messages de bouche à oreille électronique. / The electronic word of mouth has grown considerably the last years especially with the proliferation of online platforms like social networks. Treating the specific case of the characteristics of online messages (the valence strength and arguments), this work has helped us in a first exploratory step to learn the language of the Internet to create our own scenarios, to know the main questions of users about the credibility and the trust and usefulness of these messages. This research and literature review have enabled us to propose a conceptual model to pivot about the characteristics of word-of-mouth messages online and influences on consumer behavior. Through a confirmatory analysis we tested and validated the proposed model and accepted and rejected some of our supposed hypothesis. The statistical output had shown that the types of messages influence the perceived credibility, purchase intent and recommendation. Moderator variables related to the characteristics of the message receiver moderate these relationships. Mediating variables (ie perceived trust and perceived usefulness of messages) are considered fundamental for the evaluation of electronic word of mouth messages.

Liu, Ke. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 41-46). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Related Work --- p.7 / Chapter 2.1 --- Keyword Expansion --- p.7 / Chapter 2.2 --- Content-based Image Search and Visual Expansion --- p.8 / Chapter 3 --- Algorithm --- p.12 / Chapter 3.1 --- Overview --- p.12 / Chapter 3.2 --- Visual Distance Calculation --- p.14 / Chapter 3.2.1 --- Visual Features --- p.15 / Chapter 3.2.2 --- Adaptive Weight Schema --- p.17 / Chapter 3.3 --- Keyword Expansion --- p.18 / Chapter 3.4 --- Visual Query Expansion --- p.22 / Chapter 3.5 --- Image Pool Expansion --- p.24 / Chapter 3.6 --- Textual Feature Combination --- p.26 / Chapter 4 --- Experimental Evaluation --- p.27 / Chapter 4.1 --- Dataset --- p.27 / Chapter 4.2 --- Experiment One: Evaluation with Ground Truth --- p.28 / Chapter 4.2.1 --- Precisions on Different Steps --- p.28 / Chapter 4.2.2 --- Accuracy of Keyword Expansion --- p.31 / Chapter 4.3 --- Experiment Two: User Study --- p.33 / Chapter 5 --- Conclusion --- p.39

En esta investigación se analiza Los canales de comunicación audiovisual de Instagram y su relación con la intención de compra de ropa deportiva de moda en mujeres de 18 a 35 años de nivel socioeconómico A de San Borja, Surco, San Isidro y Miraflores en el presente año. En base a esto, la hipótesis planteada es que los canales de comunicación audiovisual de Instagram se relacionan con la intención de compra de ropa deportiva en mujeres. De esta manera, la investigación describe el marketing de boca a boca y su evolución en el tiempo, el desarrollo del concepto mencionado en las redes sociales, ahondando en Instagram. Asimismo, se describe lo que es una intención de compra, con apoyo del proceso de compra, comportamiento del consumidor y el ZMOT1. Finalmente, se detallan la evolución y características de Instagram, haciendo hincapié en las “fotos”, “videos”, “stories” e “Instagram Tv”. La investigación es de tipo descriptivo, menciona los 4 canales de comunicación audiovisual y los actores como “seguidos”, “influencers” y “cuentas de las marcas” que participan en esta red social. La intención de compra en Instagram se ve influenciada de forma diferente por canal, actor y la actividad que este pueda hacer al momento de publicar algún contenido. / This research analyzes the audiovisual communication channels of Instagram and its relationship with the intention of buying fashionable sportswear in women from 18 to 35 years of socioeconomic status A of San Borja, Surco, San Isidro and Miraflores in the current year. Based on this, the hypothesis is that Instagram's audiovisual communication channels are related to the intention of buying sportswear for women. In this way, the research describes word of mouth marketing and its evolution over time, the development of the concept mentioned in social networks, delving into Instagram. In addition, the purchase intention, the purchase process, the consumer's behavior and the ZMOT are described. Finally, the evolution and characteristics of Instagram, how to make disabilities in the "photos", "videos", "stories" and "Instagram TV" are detailed. The research is descriptive, the 4 channels of audiovisual communication and the actors as "followed", "influencers" and "accounts of the brands" that participate in this social network. The intention to buy on Instagram is influenced differently by channel, actor and the activity that can be done when publishing some content. / Trabajo de investigación

The purpose of this paper is to discuss reciprocity and the role it plays in helping us understand interactions between parties in accounting settings. The concept of reciprocity states that individuals will reward kind behaviors and punish unkind behaviors. (Fisher et al. 2015; Fehr and Gächter 2000; Fehr and Gächter 1997). When trying to trace the origins of the theory of reciprocity, it is useful to track the initial constructs on which it is built from various literary sources. This process contributes to developing an understanding of how reciprocity is used to explain behaviors in the workplace. The notion of reciprocity has a long history and is defined in many iterations of social literature dating back to ancient philosophers. Roman politician Cicero, for example, stated: “there is no duty more indispensable than that of returning a kindness” and “all men distrust one forgetful of a benefit” (Gouldner 1960). This early philosophical sentiment exemplifies the integral role positive reciprocity plays in society and the potential avarice an individual may encounter when not returning positive actions with displays of positive reciprocity. Through this review, I gather literature that builds on the concept of reciprocity. I organize commonly found themes and organize settings previously used to focus on the multiple constructs to build upon reciprocity.

Recently, task-based research motivated by a Vygotskian theoretical perspective has led to studies that demonstrate how the task-as-workplan is interpreted and reshaped by learners in actual performance (Coughlan and Duff, 1994). The ability of learners to set their own ‘tasks’ suggests that researchers need to investigate how individual students react to the tasks they have been asked to perform (Ellis, 2003). To date, there have been very few systematic studies on learner and teacher perceptions in this particular field. Four studies conducted by Kumaravadivelu (1989, 1991), Slimani (1989, 1992), Block (1994, 1996), and Barkhuizhen (1998) have shed light on the learner and teacher perception of classroom events. This study has continued the investigation into how individual students react to the tasks they have been asked to perform. In particular, it has focussed on four potential mismatches between teacher intention and learners’ interpretation of task, previously identified in a study by Kumaravadivelu (2003): instructional, pedagogic, procedural and strategic. The study aimed to look at teacher and learners’ perceptions and therefore a qualitative approach was used to gather information. The study was triangulated on two levels, using a variety of data (data triangulation) and different methods (questionnaires and interviews) to collect the data (methodological triangulation). Sixteen students studying for a Certificate in English at the School of Languages and Social Sciences at Auckland University of Technology were asked to perform a task and then complete a questionnaire which was designed to elicit information regarding the four potential mismatches, between teacher intention and learner interpretation, referred to above. Four pairs of students participated in each of the two tasks. Four students, one from each pair was then interviewed in order to elicit more in-depth information regarding the four mismatches referred to above. The teacher was also interviewed after the task had been completed. The student answers from the questionnaires were compared with the data gathered from the student and teacher interviews. The findings seem to show that two mismatches between teacher intention and learners’ interpretation were evident, namely instructional and pedagogic. There was no clear evidence of a strategic or procedural mismatch. Despite the small sample size, the study seems to show that mismatches are identifiable. Given the importance of perceptual mismatches and the fact that they are part of the practice of everyday teaching, it is important that we try to identify as many mismatches as possible in future research. It is reasonable to assume that the narrower the gap between teacher intention and learner interpretation, the greater the chances of achieving learning and teaching objectives (Kumaravadivelu, 2003).

<p> </p><p> </p><p><strong>ABSTRACT</strong></p><p> </p><p><strong>Date: </strong>June 2, 2009</p><p><strong>Programme: </strong>MIMA – International Marketing<strong> </strong></p><p><strong>Course:</strong> EF0705 Master Thesis</p><p><strong>Authors:</strong> Sutanita Thavornchak, Waritthar Taratanaphol</p><p><strong>Tutor:</strong> Joakim Netz</p><p><strong>Title:</strong> Factors influencing online purchase intention: Domestic Airline E-ticket in Thailand</p><p><strong>Introduction: </strong>Internet has become one of the most powerful tools to enhance the performance in every industry and business, including travel and tourism industry as well.  The industry has been dramatically changed by the internet in form of information search, trip planner, particularly the introduction of a new online reservation system, an electronic ticket (E-ticket). Moreover, there currently is an attempt of the International Air Transport Association (IATA) to change all 240 airlines around the world into this E-ticket system. About the e-ticket system in Thailand, many airlines have already adopted this system and tried to introduce it to their customers. However, the statistic was shown that only 24% of the internet user has experienced with it, which is pretty low comparing to some other countries. Consequently, the airlines have been trying to improve and enhance their systems in order to encourage the customers to purchase the electronic ticket.</p><p><strong>Problem:</strong> “What are the factors that influence intention to make an online purchase of airline e-ticket?”<strong> </strong></p><p><strong>Purpose: </strong>The purpose of this research is to explore the factors influencing the intention to purchase the domestic airline e-ticket in Thailand, and also to investigate whether there are any differences between e-ticket adopters and non-adopters.</p><p><strong>Method</strong>:         The research is based on quantitative research by using online self-administered survey. The list of respondents was from two travel agencies in Thailand. The questionnaires were sent out to 350 respondents and a total of 253 usable respondents were collected in this research. The questionnaires were designed based on Technology Acceptance Model (TAM). The model comprises of Perceived Usefulness (PU) and Perceived Ease of use (PEOU). In addition, the theory of Perceived Risk (PR) is also added to be the third construct in the model.</p><p><strong>Conclusion: </strong>The findings indicate that the all three constructs have different impacts on intention to purchase of e-ticket adopter and e-ticket non adopter. Perceived Usefulness (PU) is the only construct that influences e-ticket adopter while all three construct have significant impact on future intention to purchase of e-ticket non adopter. Convenience factor tends to be the most important one in Perceived Ease of Use (PEOU) for e-ticket non adopter whereas product information and accessibility is more important to e-ticket adopter in Perceived Usefulness (PU). Security and privacy are the major concern in Perceived Risk (PR) when buying e-ticket. However, there are additional factors which affect the future intention to purchase exclude from the three constructs studied.</p><p><strong> </strong></p><p><strong> </strong></p><p><strong></strong></p><p> </p>

<p>Uppsatsens huvudsakliga syfte har varit att mäta vilka attityder och hur starka intentioner som finns till köp av kakel och klinker. Undersökningen skulle resultera i en kartläggning av både befintliga och potentiella kunders attityd och intention till inköp av kakel och klinker.</p><p>För genomförandet av undersökningen valdes en kvantitativ forskningsansats. En enkät med frågor baserade på Ajzen’s teori om det planerade beteendet (The Theory of planned Behavior) delades ut till 9 butiker och besvarades av totalt 167 respondenter vilka har ingått i analysen. Frågorna i enkäten har tagit fasta på kundens attityd till det specifika beteendet, det vill säga till det eventuella inköpet av kakel och klinker, dennes uppfattade subjektiva norm kring köpet samt vilken egenuppfattad förmåga han eller hon har haft till att genomföra beteendet. Genom dessa uppgifter har det gått att förutsäga vilken intention kunden har haft till att faktiskt utföra beteendet.</p><p>De slutsatser som har gått att dra efter genomförandet av den här undersökningen är att attityden till köp av kakel och klinker överlag är positiv, men går att förstärka. De respondenter som har ingått i undersökningen har jämförts utifrån olika aspekter såsom inkomst, boendeform och ålder. Jämförelser har visat att oavsett vilka variabler som studerats har ingen av grupperna varit särskilt utmärkande när det gällde attityden till beteendet. Av detta har slutsatsen kunnat dras att respondenterna överlag har en likvärdigt positiv attityd till beteendet; köp av kakel och klinker. Även köpintentionen har jämförts utifrån ovan nämnda variabler. Slutsatsen som har kunnat dras av den analysen tyder på att intention till köp existerar, men är låg, det vill säga svagt positiv. Vilka komponenter som styr intentionen går att utläsa mer noggrant i Kapitel 4; (resultatkapitlet). Uppsatsen har avslutats med ett antal rekommendationer till Kakelplattan AB om vad de bör tänka på i sin framtida marknadsföring.</p>

Under driving in the digital trend, the 3C product becomes an important strength that pushes the market growth and isn¡¦t allowed to ignore. Along with the information circulates quickly, the favor of the consumer continuously changes. The manufacturer makes use of progress the science and technology technique to integrates enrich and the more high-quality content into more diverse device. However cell phone becomes the main consume communication electronics product currently, under the convenient need of the consumer, as Dan Steinbock (2006) speaks of in the book "The Mobile Revolution: The Making of mobile services worldwide"¡GThe mobile communication is experiencing the huge change period of the voice into the data. Global mobile market and service development just turns in and will become the next star level of mobile communication product. Today the flourishing times of science and information technology progresses, in order to maintain the competitive advantage, the enterprise continuously pursues the innovation and growth. However the cellular phone product life cycle tends in the maturity and the market is gradually saturated, the manufacturer stimulates the need of the consumer by promoting the innovation of the product. This research is inquiring the influence between the innovation of the product and personal creative characteristics into the intention of buying high-tech product for the consumer, expecting to provide enterprise on the development and marketing the decision reference. As case example with high creative-iPhone that Apple Inc. will soon appear on market. To adopt the convenience sampling questionnaire from April 2nd till 30th and collect valid 240 samples to carry on the data analysis. The result finds the innovation of product and the consumer innovative characteristic present the obvious influence of the purchase willing, and the product innovation through the consumer innovation would indirect affect the purchase willing. The creative sensitive degree for young generation is higher, particularly valuing to the function of the product in the need of the occupation, obviously, the innovation is also widespread to be subjected to the general public accept now. The successful innovation originates new science and technology and new market field appear, enterprise continuously applies innovation, but the most important is providing the product of customer need, and establishes the brand image, then raises the customer loyalty to reach the life simply is a beautiful realm.