2 resultados para SAW
em Repositório Digital da UNIVERSIDADE DA MADEIRA - Portugal
Resumo:
INTRODUCTION With the advent of Web 2.0, social networking websites like Facebook, MySpace and LinkedIn have become hugely popular. According to (Nilsen, 2009), social networking websites have global1 figures of almost 250 millions unique users among the top five2, with the time people spend on those networks increasing 63% between 2007 and 2008. Facebook alone saw a massive growth of 566% in number of minutes in the same period of time. Furthermore their appeal is clear, they enable users to easily form persistent networks of friends with whom they can interact and share content. Users then use those networks to keep in touch with their current friends and to reconnect with old friends. However, online social network services have rapidly evolved into highly complex systems which contain a large amount of personally salient information derived from large networks of friends. Since that information varies from simple links to music, photos and videos, users not only have to deal with the huge amount of data generated by them and their friends but also with the fact that it‟s composed of many different media forms. Users are presented with increasing challenges, especially as the number of friends on Facebook rises. An example of a problem is when a user performs a simple task like finding a specific friend in a group of 100 or more friends. In that case he would most likely have to go through several pages and make several clicks till he finds the one he is looking for. Another example is a user with more than 100 friends in which his friends make a status update or another action per day, resulting in 10 updates per hour to keep up. That is plausible, especially since the change in direction of Facebook to rival with Twitter, by encouraging users to update their status as they do on Twitter. As a result, to better present the web of information connected to a user the use of better visualizations is essential. The visualizations used nowadays on social networking sites haven‟t gone through major changes during their lifetimes. They have added more functionality and gave more tools to their users, but still the core of their visualization hasn‟t changed. The information is still presented in a flat way in lists/groups of text and images which can‟t show the extra connections pieces of information. Those extra connections can give new meaning and insights to the user, allowing him to more easily see if that content is important to him and the information related to it. However showing extra connections of information but still allowing the user to easily navigate through it and get the needed information with a quick glance is difficult. The use of color coding, clusters and shapes becomes then essential to attain that objective. But taking into consideration the advances in computer hardware in the last decade and the software platforms available today, there is the opportunity to take advantage of 3D. That opportunity comes in because we are at a phase were the hardware and the software available is ready for the use of 3D in the web. With the use of the extra dimension brought by 3D, visualizations can be constructed to show the content and its related information to the user at the same screen and in a clear way. Also it would allow a great deal of interactivity. Another opportunity to create better information‟s visualization presents itself in the form of the open APIs, specifically the ones made available by the social networking sites. Those APIs allow any developers to create their own applications or sites taking advantage of the huge amount of information there is on those networks. Specifically to this case, they open the door for the creation of new social network visualizations. Nevertheless, the third dimension is by itself not enough to create a better interface for a social networking website, there are some challenges to overcome. One of those challenges is to make the user understand what the system is doing during the interaction with the user. Even though that is important in 2D visualizations, it becomes essential in 3D due to the extra dimension. To overcome that challenge it‟s necessary the use of the principles of animations defined by the artists at Walt Disney Studios (Johnston, et al., 1995). By applying those principles in the development of the interface, the actions of the system in response to the user inputs became clear and understandable. Furthermore, a user study needs to be performed so the users‟ main goals and motivations, while navigating the social network, are revealed. Their goals and motivations are important in the construction of an interface that reflects the user expectations for the interface, but also helps in the development of appropriate metaphors. Those metaphors have an important role in the interface, because if correctly chosen they help the user understand the elements of the interface instead of making him memorize it. The last challenge is the use of 3D visualization on the web, since there have been several attempts to bring 3D into it, mainly with the various versions of VRML which were destined to failure due to the hardware limitations at the time. However, in the last couple of years there has been a movement to make the necessary tools to finally allow developers to use 3D in a useful way, using X3D or OpenGL but especially flash. This thesis argues that there is a need for a better social network visualization that shows all the dimensions of the information connected to the user and that allows him to move through it. But there are several characteristics the new visualization has to possess in order for it to present a real gain in usability to Facebook‟s users. The first quality is to have the friends at the core of its design, and the second to make use of the metaphor of circles of friends to separate users in groups taking into consideration the order of friendship. To achieve that several methods have to be used, from the use of 3D to get an extra dimension for presenting relevant information, to the use of direct manipulation to make the interface comprehensible, predictable and controllable. Moreover animation has to be use to make all the action on the screen perceptible to the user. Additionally, with the opportunity given by the 3D enabled hardware, the flash platform, through the use of the flash engine Papervision3D and the Facebook platform, all is in place to make the visualization possible. But even though it‟s all in place, there are challenges to overcome like making the system actions in 3D understandable to the user and creating correct metaphors that would allow the user to understand the information and options available to him. This thesis document is divided in six chapters, with Chapter 2 reviewing the literature relevant to the work described in this thesis. In Chapter 3 the design stage that resulted in the application presented in this thesis is described. In Chapter 4, the development stage, describing the architecture and the components that compose the application. In Chapter 5 the usability test process is explained and the results obtained through it are presented and analyzed. To finish, Chapter 6 presents the conclusions that were arrived in this thesis.
Resumo:
This thesis examines the concept of tie strength and investigates how it can be determined on the fly in the Facebook Social Network Service (SNS) by a system constructed using the standard developer API. We analyze and compare two different models: the first one is an adaptation of previous literature (Gilbert & Karahalios, 2009), the second model is built from scratch and based on a dataset obtained from an online survey. This survey took the form of a Facebook application that collected subjective ratings of the strength of 1642 ties (friendships) from 85 different participants. The new tie strength model was built based on this dataset by using a multiple regression method. We saw that the new model performed slightly better than the original adapted model, plus it had the advantage of being easier to implement. In conclusion, this thesis has shown that tie strength models capable of serving as useful friendship predictors are easily implementable in a Facebook application via standard API calls. In addition to a new tie strength model, the methodology adopted in this work permitted observation of the weights of each predictive variable used in the model, increasing the visibility of the factors that affects peoples’ relationships in online social networks.