Inhaltsangabe:Introduction: Recent years have witnessed the great popularity of online social networking services, in which millions of members publicly articulate mutual friend- ship relations. Social network services have become a major application in the internet. Correspondingly the number of provider such social net- work services has multiplied and accommodates estimated 272 million users worldwide (Universalmccann, 2008). The mass adoption of social networking websites points to an evolution in human social interaction. These sites let the user create an identity namely their profile, which they fill with personal information. These identities can then be searched and relationships among the users can be made. A user can make friends virtually and by that creates his own social circle, that is why it can also be regarded as a reflection of the real world. Most of the users are part in more than one social network, which creates problems in terms of identity and relation management. At the moment there seems to be no consolidation among the services, but a further fragmentation and by that also a fragmentation of information. In the real world people can be easily identified, but this is not possible in the internet as there is no physical contact. People using assumed names as an identifier which may be different on every platform. On top of this it is difficult to manage all the contacts which are spread over several services. At the moment the social network services do not o er ways to get the data out of their platforms to reuse it somewhere else. The use of separate networks may be wanted by the users regarding order and different roles they can slip into. In spite of these aspects there is an increasing demand for reusing and sharing the contact data to be able to manage the online friendships . To overcome the disadvantages of fragmented data central storage has to be established. In combination with exchange mechanisms it would make data reusable, which means all the social networks the user is part of could be synchronised. This is especially useful when entering a new network. It is like moving into a new city and already know some people. Inevitable for such a scenario is that the information of the social networks are portable and that the user can be uniquely identified. There are e orts to achieve this goal, but up to now only partial problems have been solved. An overall concept seems not possible at the moment due to technical crudity and the difficulty to bring the different interests of users and social network services in line. Nevertheless there are existing standards that can be combined to one concept. This thesis will first analyse the needs and existing solutions in order to develop a prototype which is able to synchronise contacts in social networks. Inhaltsverzeichnis:Table of Contents: List of Figuresiii 1.Introduction1 2.Social network services3 2.1Definition3 2.2Present SNS usage4 2.3Relation and identity management in SNS5 2.4Present data portability and its problems9 2.4.1Political situation9 2.4.2Technical situation10 3.Current data portability solutions14 3.1Microformats14 3.2XRDS-simple17 3.3Oauth18 3.4RDF19 3.5OpenID plus Attribute Exchange Extension20 4.Concept for a SNS metadirectory22 4.1Goals22 4.2Concept description22 5.Development of the prototype26 5.1Analysis26 5.1.1Functional and data description26 5.1.2System architecture26 5.1.3Interface description27 5.1.4Usage scenario28 5.1.5Data model29 5.2Design30 5.2.1Data design30 5.2.2Architectural and component-level design31 5.2.3Interface description33 5.3Implementation36 5.3.1Setting up the OpenID server and the SNS36 5.3.2Attribute Exchange - Fetch Message36 5.3.3Pro cessing the FOAF data37 5.3.4Attribute Exchange Store Message38 5.4Appraisal of results40 6.Summary and Outlook42 References44 AAppendix46 A.1Source code digest46 Textprobe:Text Sample: Chapter 2.4, Present data portability and its problems: Political situation: As already broached portable data is required to have a greater benefit of using SNSs. First of all however there are political issues affecting the access to the data. Besides small non-commercial SNSs the most important ones are companies who want to maximize their profits, so that they may have reasons to resist data portability. A crucial factor for such companies is the amount of users they have. Through that the platform increases in value, because the service is more attractive to users, as they find much more contacts and network effects get fortified. More users also means more traffic and this leads to better advertisement revenues. The information the SNSs have about the users even allow for target-group-specific advertisement. The data is part of the business model. Big SNSs with millions of users and all their individual data hold out a huge treasure of personal data and it is even more valuable as it also includes the connections of people among each other. So these companies may refuse to open up their platform, because they are interested in a proprietary access to the monetisable data especially when the service is already very popular and has reached the critical mass of users. According to the survey about the usage of so cial networks the most popular feature is messaging friends, so a SNS can also be regarded as an address book and users visiting the site regularly to communicate with their contacts. This could change and would reduce the traffic for the SNS, if the data is available elsewhere also. Another disadvantage would be that competitors could easily tout for the users when it is so easy to take along the contacts from other services. Consequently at the moment such an initiative can only be advanced from the bottom. Smaller SNSs working together to become a strong counterpart to the big players that may force them to open up as well. Besides these aspects data portability must also keep the balance of privacy and usability. Privacy is just as important as openness and if it would become too easy to share data with external services security privacy issues may occur. This is especially true for a central architecture when one identity provider stores all the information. In this case the identity provider stores very valuable information. Moreover it can monitor the users activity, because it is involved in every authentication process. Technical situation: The current use of data portability concepts and the available technologies is not prevalent. Most of the current SNSs originated as an independent platform without an interface to the outside world. The most popular social networks like MySpace and Facebook are so called walled gardens , so do not o er possibilities to export or reuse the data available on their platform and the access to information is restricted to members. Thus the data is bound to the SNS and its proprietary formats. This is very different from the open nature of the web and leads to redundant storage of data. In addition the user-authentication is decentralized and has to be done for each SNS itself. In contrast to that there is OpenID, a identity system that lets people use a single username and password to log in and authenticate themselves to OpenID-compliant websites. Although there are attempts to intro duce this single sign on solution most of the SNSs have an own user account and authentication mechanism. This involves that the user has to to maintain his data on every platform separately. Furthermore separate profiles lead to the problem of finding contacts. The user have to do it again for each platform and as there is no general identifier like there would be in case of a single sign on mechanism it can be hard to find a contact. One and the same may have registered with different user names or e-mail addresses on each platform, so that a user might miss a relationship he would have liked to establish. A decentralized approach to solve this problem is XFN (cf. Microformats ), which however is not widely used at the moment. The most important approach using this technique is Googles Social Graph (Google, b). Google provides an API to collect so cial network information from the web. Like the search engine is looking for words, the web is crawled for relationships. The API can be used to follow the links to friends, which in turn points to other profiles of themselves and by that the user can discover an existing friend on a new platform. This concept however does not work out at the moment as there are not enough SNSs which save their data in the XFN-Format. Instead the social network fatigue problem or social network update/maintenance problem is wide-spread, which means that people are tired of registering, re-enter their profile information and re-declaring their friends on every site. But there is a tendency to open up the services for reuse of the data. First of all RSS has become a standard feature for the majority of SNSs. RSS is a standardized representation of information designed to syndicate information from different sources, which is mostly used for sources with frequently updated information. Facebook for example offers access to its data in form of RSS-Feeds. By that users can follow status updates of their friends, their news-feed etc. also on other places than Facebook. Another way to open up the SNSs seems to be more important and more crucial for the success of the service at the moment namely providing an API. An API enables third party developers to reuse the data or even write applications that will run on the SNS platform. Regarding the reuse of data the website is not the only access of the service any more, for example one can use the service from a mobile or desktop application. Depending on the type of service this can become the preferred way of using it. For instance the content of the microblogging platform Twitter is changing so fast, that it is not practical to check the website regularly. For this use case a desktop application which pulls the information from the service automatically improves the usability a lot. Hence an API can make a service much more valuable. The same is true of an API for applications that are embedded in the SNS platform. In 2007 Facebook was the first popular SNS introducing such an interface. Creating a social application can be seen as a win-win situation. The SNS broadens the set of features it provides and the developer do not have to care of collecting enough users, because the application can access the already existing data of the SNS. In addition to the proprietary API of Facebook Google tries to establish an interface that can be used on more than one platform. Applications that implement the interface of Googles Open Social (Google, a) can be used on all the SNSs that support the API.In combination with exchange mechanisms it would make data reusable, which means all the social networks the user is part of could be synchronised. This is especially useful when entering a new network.
|Title||:||Data portability and relation management in social web applications|
|Publisher||:||diplom.de - 2008-12-02|