Extending Social Networking Services toward a ... - Springer Link

Extending Social Networking Services toward a Physical Interaction Scenario Camilo Vergara, Sergio F. Ochoa, Francisco Gutierrez, and Juan Rodriguez-Covili Computer Science Department, Universidad de Chile Av. Blanco Encalada 2120, 3rd Floor, Santiago, Chile {cavergar,sochoa,frgutier,jrodrigu}@dcc.uchile.cl

Abstract. Mobile computing provides ubiquitous access to social networking services allowing computer-mediated interaction among its members. This article proposes a new and complementary interaction paradigm promoting faceto-face encounters among community members, based on their physical proximity. Therefore, the virtual space for interactions is extended towards the physical one. The proposal was implemented through a mobile ubiquitous application, which was evaluated to understand its usability, perceived usefulness and performance. The preliminary results of such evaluations are highly encouraging. Keywords: Social networking services, ubiquitous computing, hybrid interaction paradigm, physical scenario, mobile ad hoc networks.

1

Introduction

Social Networking Services (SNS) allow users to connect and interact with others who have different beliefs or interests [8]. These systems make deeper the relationship with already known people, reinforcing and strengthening the existing social ties [13]. Mobile devices provide ubiquitous access to SNS allowing a virtual interaction among users. However, most communities are partially virtual, so they require support for interacting not only in the virtual space, but also in the physical one [5]. This paper proposes an interaction paradigm to support this hybrid social scenario, making current SNS more ubiquitous. System availability and privacy are important issues to consider in these systems design [1]. In order to evaluate this hybrid interaction paradigm, a mobile ubiquitous application was implemented. The tool, named Lukap, was evaluated and the preliminary results indicate the system would be appropriate to support partially virtual communities (PVC). The extension of the current SNS interaction paradigm takes advantage of the physical location of members. Based on that information and the privacy preferences, the application promotes face-to-face encounters. This functionality is highly available since Lukap requires just the communication support of a Mobile Ad hoc Network (MANET) [3] and the social data each user keeps locally in his/her device. Next section reviews the related work on supporting systems for partially virtual communities. Section 3 introduces the hybrid social interaction space. Section 4 describes Lukap and its main components. Section 5 presents the evaluation settings and obtained results. Finally, section 6 presents the conclusions and future work. J. Bravo, D. López-de-Ipiña, and F. Moya (Eds.): UCAmI 2012, LNCS 7656, pp. 208–215, 2012. © Springer-Verlag Berlin Heidelberg 2012

Extending Social Networking Services toward a Physical Interaction Scenario

2

209

Social Networking Services and Partially Virtual Communities

Social networks involve users who share similar interests and practices, and who interact regularly over a common communication channel [14, 15]. In this paper we are particularly interested in supporting interactions among members of a PVC. Gutierrez et al. define a PVC as a group of people who interact around a shared interest or goal using technology-mediated and face-to-face mechanisms [5]. Depending on the community context, different PVCs involve different degrees of virtualness. Typically, SNS lack of support for physical interactions. Location-aware community systems should support ad-hoc interactions with friends, family, colleagues and strangers. Also, they should show if a public resource is currently used, facilitate task coordination and help people avoid others [6]. Facebook and Twitter currently offer a way to label each contribution with tags linked to their location, either chosen by the author or generated through the device. Foursquare is a location-based SNS that can be used to support physical encounters between users. They can register different places, share tips with friends and others, and connect accounts with other SNS. The users’ location reference is based on the information that they declare, which has two main problems: (1) if a user wants to be contacted, s/he must be aware to record such information, and (2) the location information that supports the interactions among members could be accidentally or intentionally wrong or outdated. On October 2011, Foursquare v4.0 was launched with a Radar feature. It consists on an automatic notification service where a user may be aware of spots or people that are close to his/her current location. However, no attention was given to enhance this feature in Foursquare v5.0. Moreover, it is only supported on iPhone 4 and 4S devices running iOS 5. Lindqvist et al. examined how and why people use Foursquare. They found people tend to explore places, coordinate with friends, signal availability to friends, among others [9]. Moran et al. developed a ubiquitous application named meetU, which supports social networking through an ad hoc communication infrastructure [11]. This SNS is available through the users’ mobile devices and it provides not only user interaction services, but also social and emotional awareness to mobile workers. The Mobilis project provides a reusable toolkit to develop mobile location-based social software with functionality like group communication, importing contacts from existing SNS, location sharing, proximity detection, among others [17]. The authors also proposed to support temporal and spatial restrictions for group visibility and the ability to users to join those groups, as they would provide an incentive for users to be at a physical place to login and interact with other nearby users [10].

3

The Hybrid Interaction Space

Figure 1 shows the hybrid interaction space composed of a virtual and a physical space. Interaction among users in the virtual space is supported by Internet and typical SNS. Interactions in the physical world (i.e. face-to-face meetings) are supported by Lukap. The application uses a MANET [3] as a communication channel and also supports information from the SNS, which is stored into the devices of the members through an on-demand process. Each member downloads and keeps locally his/her

210

C. Vergara et al.

own information from the SNS s/he belongs to, including the privacy preferences. Therefore, the services for supporting physical interactions do not require access to Internet or a SNS server in real-time. In other words, the local information about SNS and the communication capabilities of the users’ mobile devices are enough to allow Lukap to promote interactions in the physical scenario.

Fig. 1. Hybrid interaction space to support PVC activities

A full-duplex data synchronization process is used to keep the coherence of the shared information between Lukap and the SNS. This process is also performed ondemand by users of mobile devices. Such a process exchanges information with the SNS server through a provided API to interact with third-party applications [7]. Lukap users can set their visibility preferences. If s/he is visible and other member is physically close, then an alarm message will be triggered on the devices screens of both users. Once it is received, the users will decide if they want to interact face-toface by making a phone call to coordinate a meeting point, or using a GPS service or an Indoor Positioning System (IPS) to physically locate the target person. Depending on the physical scenario and on the number of people using Lukap, the detection service may identify the presence of members located up to 150 meters from other user.

4

The Lukap Application

Lukap can automatically detect other members within the contacts of a particular user. This requires no supplementary action, so this service can be considered as an extension (or complement) to the user senses. Users can import their contacts from other SNS, allowing people to interact through any of the communication channels provided by Lukap. A user can set his/her status as available, unavailable, busy or disconnected. Figure 2a shows the main user interface of Lukap. In this case, the user set his status as available to his family, but busy to his friends. Figure 2b shows how a user can import his/her contacts from a SNS. Lukap was developed in C# using the Microsoft .NET 4 framework and it is currently available on Windows 7. The application uses HLMP API [16] as the main infrastructure to create and manage the MANET. Also, it guarantees that communication among users is secure, and that personal information from a user will not be accessible to other members through the network.

Extending Social Netw working Services toward a Physical Interaction Scenario

211

Device detection is provided by HLMP, aand community member detection by Lukaap. HLMP also provides a reference distannce (number of hops) between a user aand his/her contacts.

Fig. 2a. Lukap Main Userr Interface

Fig. 2b. Importing Contacts from other SNS S

Notifications are triggerred each time a gap is detected. Most of them are invisiible to end-users because their goal g is to keep updated the presence information in a phhysical environment. Figure 3 presents the Lukap architecture, which considers the innteraction between the virtuall and the physical spaces. The virtual space is represennted by the SNS that interact with w Lukap using their public APIs [7]. Since each AP PI is different, there is a commu unication layer composed of several controllers, each one specifically designed to intteract with a particular SNS. An event manager acts ass an intermediary between the SNS S controllers and the Lukap services. Typically, it m manages the input/output of thee invoked services, providing thus a unique interface w with the SNS, other mobile nod des, and any external application that wants to collaborrate on-demand with Lukap. The application main seervices are grouped in four categories: social informatiion, supporting services, user in nterface, and communication system. This last one is implemented through the HLM MP API, which is responsible of creating and maintainning the MANET and providing g message exchange among nodes available in the physical scenario [12]. The user inteerface must expose through the user interface the serviices and awareness mechanismss required to perform each activity. The supporting serviices perform functions that are used u by other services to expose complex and rich funcctionality. This involves six seervices: a context discovery, a context-aware self-adapptor, an activity estimator, a ressources handler, a users detector and positioning systtem. Some of these components come from the HLMP API coordination services. The context discovery service s is responsible of identifying and notifying conttext changes to other Lukap serrvices, and also recording and retrieving context variabbles. The context-aware self-adaaptor is in charge of self-adapting the application when the environment changes consid derably.

212

C. Vergara et al.

Fig. 3. Hybrid interaction space

5

The activity estimator infers the type of activity being performed by a user. Based on such information, it deploys on the user interface the services that could be required by him/her. The resources handler is responsible of managing the private and shared resources of each node. The users detector informs whether a particular mobile user is available or not for interactions, and also informs the connection status of all MANET members. The users positioning system is an IPS that helps find a mobile user in a physical scenario. The social information component involves four services: user profile, social linkages, social content and content linkages. The user profile service allows creating and maintaining the user profile, including privacy issues. The social linkages service maintains the social links among users and also provides such information to other Lukap services. The social content and content linkages manage interrelated information that a user wants to share with others.

Preliminary Results

The Lukap usefulness and usability was evaluated through a focus group with six software designers. Also, its performance was evaluated in a real scenario. Next sections present the evaluation processes and the obtained results. 5.1

Usefulness and Usability

The software designers participating in the focus group were between 23 and 25 years old. All of them had at least two years of experience as software designers. Three had previous experience evaluating usability of software interfaces. Two hypothetical situations were presented (Table 1). Each one was divided in two stages: (1) presentation and (2) discussion where participants could propose solutions to the situations. This gave us an idea of which services are mandatory and optional for users. The main issue identified is the lack of ways to perceive the availability of contacts. Among the given solutions, three participants proposed to display the current user’s position and availability using a SNS. One participant pointed out that a ubiquitous application would be useful because a user does not need to perform any action to indicate his/her location and availability for social contact. Other alternatives based on remote access to online SNS were proposed. However, these represent a significant limitation since a user must remain connected in order to be visible for others.

Extending Social Networking Services toward a Physical Interaction Scenario

213

Table 1. Hypothetical situations used to evaluate the usability and usefulness of Lukap Situation 2: Alice and Bob took the same course at college, and they are working together. Their deadline is in a couple of hours, and they have not finished yet. Alice does not know where Bob is. She tries to reach him by phone, email, Facebook and Twitter, but he is not accessible.

Situation 1: It is Friday evening and Alice is sharing a drink with Bob at a bohemian quarter. Alice has to leave early and Bob evaluates the possibility of staying for a while if he manages to find a friend nearby. Since the area is small, he walks around and tries to find some friends.

Afterwards, we presented the general features and the user interface of Lukap, as a possible solution to address both situations. The designers analyzed Lukap and could ask questions and discuss among them. Five participants praised the usefulness of the application as a way to enhance physical interaction among SNS members in a ubiquitous way. Moreover, it was widely appreciated that Lukap runs over a MANET, since no access to infrastructure-based communication networks is required. The participants filled a 5-point Likert scale survey that helped us to understand how suitable are the user interfaces and the services provided by Lukap. Figure 4 shows the items of the survey and the median score of the participants’ answers. The designers claim the Lukap services are easy to use and consider a broad range of functionalities. Some elements of the user interface have to be redesigned in order to make them suitable for the end-users’ mental model as Lukap currently looks like a chat room. There were also suggestions on including location awareness features, such as displaying contacts in a map or a radar view indicating how far and in which direction a user is from his/her contacts.

Overall, I am satisfied with this application. I would be likely to use Lukap in the future. I liked using the interface of this application. The offered functionalities met my… Overall, the application is easy to use. 1

2

3

4

5

Fig. 4. Usability evaluation results for the current implementation of Lukap

5.2

Performance Evaluation

The performance was evaluated in terms of user detection capability and communication throughput. The first evaluation identified the maximum delay and detection distance. The second one allowed finding out the interactions that can be supported. Five smartphones were used in this evaluation process, and the physical scenario involved in these tests was the two-floor area of the Computer Science Department at the University of Chile, including two stairs.

214

C. Vergara et al.

All nodes remained stationary during the tests to ensure the comparability of the obtained results. The user detection process involved four scenarios using the same experimentation setting. The first scenario considered the detection of nodes to one hop of distance; the second one was to two hops, and so on. Five rounds were performed per each scenario. The observed variables were two: (1) the time spent between the MANET is created and the target user is detected, and (2) the percentage of unsuccessful detections. The obtained results are shown in Table 2. Table 2. Performance results of Lukap

Maximum delay for users detection Percentage of detection fails Communication throughput

1-hop

2-hops

3-hops

4-hops

6 sec.

8 sec.

17 sec.

92 sec.

0%

0%

20%

60%

127Kb

87Kb

42Kb

14Kb

Lukap has a good performance to detect people that are at 1-2 hops. This may represent distances up to 30-40 meters in built areas, and up to 150-200 meters in open areas.

The Lukap detection process is acceptable when there are 3 hops between the target nodes, but we can see a 20% of fails. If the distance between nodes is 4 hops the solution tends to be inappropriate, mainly because the user detection fails grow up to 60%. In order to measure the available bandwidth between users in each scenario, we transferred a file weighting 4,2MB. The results indicate that the network throughput, when nodes are to 1 or 2 hops, is enough to exchange text and also voice messages among them. After that distance, just text messages are recommended. This ensures a certain system performance that does not impact negatively on the Lukap usability.

6

Conclusions and Future Work

This article introduces a hybrid interaction paradigm for members of PVCs, implemented under a ubiquitous application named Lukap. Although there are other proposals to support or promote face-to-face interactions among community members, none of them are able to do it in a ubiquitous way. Lukap not only promotes physical interaction, but also does it without requiring access to infrastructure-based communication networks or SNS. It is expected that an application as Lukap helps increase the number of face-to-face interactions, thus keeping long-term relationships [2], developing trust among members [18] and improving people’s mental health [4]. The Lukap evaluation results indicate the user interface does not fit properly the mental model of end-users; therefore it requires improvement. Nevertheless, the results indicate the application is perceived as useful to support physical encounters. The performance evaluation results indicate the application is able to detect users quickly when they are up to 1 or 2 hops, and in an acceptable time when there are up to 3 hops. This indicates the application provides an interesting coverage area to support these encounters; e.g. up to 50-60 meters in built areas and up to 250-300 meters in open areas. The communication throughput of the application is good enough to allow developers implementing several interaction mechanisms between the users.

Extending Social Networking Services toward a Physical Interaction Scenario

215

As future work, we will redesign the Lukap user interface to include more sophisticated location awareness services. Acknowledgments. This work has been partially supported by the Fondecyt (Chile), grant Nº 1120207 and LACCIR, grant N° R1210LAC002.

References 1. Barkhus, L., Brown, B., Bell, M., Sherwood, S., Hall, M., Chalmers, M.: From Awareness to Repartee: Sharing Location within Social Groups. In: Proc. of CHI 2007 (2007) 2. D’Aprix, R.: The Face-to-Face Communication Toolkit: Creating an Engaged Workforce. IABC Press, San Francisco (2009) 3. De Rosa, F., Malizia, A., Mecella, M.: Disconnection Prediction in Mobile Adhoc Networks for Supporting Cooperative Work. IEEE Perv. Computing 4(3), 62–70 (2005) 4. Goffman, E.: The Presentation of Self in Everyday Life. Anchor Books, New York (1959) 5. Gutierrez, F., Baloian, N., Ochoa, S.F., Zurita, G.: Designing the Software Support for Partially Virtual Communities. In: Herskovic, V., Hoppe, H.U., Jansen, M., Ziegler, J. (eds.) CRIWG 2012. LNCS, vol. 7493, pp. 73–88. Springer, Heidelberg (2012) 6. Jones, Q., Grandhi, S.A.: P3 Systems: Putting the Place Back into Social Networks. IEEE Internet Computing 9(5), 38–46 (2005) 7. Ko, M.N., Cheek, G.P., Shehab, M., Sandhu, R.: Social-Networks Connect Services. IEEE Computer 43(8), 37–43 (2010) 8. Lampe, C., Ellison, N., Steinfield, C.: A Face(book) in the Crowd: Social Searching vs. Social Browsing. In: Proc. of CSCW 2006 (2006) 9. Lindqvist, J., Cranshaw, J., Wiese, J., Hong, J., Zimmerman, J.: I’m the Mayor of My House: Examining Why People Use Foursquare. In: Proc. of CHI 2011 (2011) 10. Lübke, R., Schuster, D., Schill, A.: MobilisGroups: Location-Based Group Formation in Mobile Social Networks. In: PerCol 2011, Seattle, United States (2011) 11. Moran, A., Rodríguez-Covili, J., Mejia, D., Favela, J., Ochoa, S.: Supporting Informal Interaction in a Hospital through Impromptu Social Networking. In: Kolfschoten, G., Herrmann, T., Lukosch, S. (eds.) CRIWG 2010. LNCS, vol. 6257, pp. 305–320. Springer, Heidelberg (2010) 12. Neyem, A., Ochoa, S.F., Pino, J.A.: Communication Patterns to Support Mobile Collaboration. In: Proc. of the 15th Intl. Workshop on Groupware, Douro, Portugal (2009) 13. Norris, P.: The Bridging and Bonding Role of Online Communities. Press/Politics 7(3), 3–13 (2002) 14. Rheingold, H.: The Virtual Community. Addison-Wesley, Massachusetts (1993) 15. Ridings, C., Gefen, D., Arinze, B.: Some antecedents and effects of trust in virtual communities. Journal of Strategic Information Systems 11, 271–295 (2002) 16. Rodríguez-Covili, J., Ochoa, S.F., Pino, J.A., Messeguer, R., Medina, E., Royo, D.: A Communication Infrastructure to Ease the Development of Mobile Collaborative Applications. Journal of Network and Computer Applications 34(6), 1883–1893 (2011) 17. Schuster, D., Springer, T., Schill, A.: Service-Based Development of Mobile Real-Time Collaboration Applications for Social Networks. In: PerCol 2010, Germany (2010) 18. Westerlund, M., Rajala, R., Nykänen, K., Järvensivu, T.: Trust and commitment in social networking – Lessons learned from two empirical studies. In: Proc. of 25th IMP 2009 (2009)