Peer-to-peer technology in collaborative learning ?· Peer-to-peer technology in collaborative learning…

  • Published on

  • View

  • Download


36 Int. J. Knowledge and Learning, Vol. 4, No. 1, 2008 Peer-to-peer technology in collaborative learning networks: applications and research issues Robert P. Bostrom MIS Department University of Georgia Brooks 312, Athens, GA 30605, USA Fax: 706 583 0037 E-mail: Saurabh Gupta* Department of Management University of North Florida 1 UNF drive, Jacksonville, FL 32258, USA Fax: 9046202782 Email: *Corresponding author Janette R. Hill Educational Psychology and Instructional Technology University of Georgia 604 Aderhold, Athens, GA 30605, USA Fax: 7065424240 E-mail: Abstract: As organisations struggle with how to develop and use individual expertise, the importance of Collaborative Learning (CL) has grown in both academic and practitioner communities. Although organisations have a large amount of individual expertise, their ability to aggregate and share it has largely eluded them. A review of educational literature points out that academic organisations learning strategies are shifting towards a more active and group-oriented learning, referred to as cooperative or collaborative learning. Educational and business organisations are currently searching for best practices and technologies for implementing CL. This paper explores how Peer-to-Peer (P2P) computing fits in the collaborative learning paradigm. P2P has great appeal for CL because it allows people to work and learn in a more natural fashion. The paper explores the existing collaborative P2P applications, identifying those most relevant to CL. The paper also compares P2P tools with client/server tools for CL within various organisational learning networks. The paper identifies key research issues concerning the use of P2P applications for CL. Keywords: Peer-to-Peer; P2P; Collaborative Learning; CL; learning networks. Copyright 2008 Inderscience Enterprises Ltd. Peer-to-peer technology in collaborative learning networks 37 Reference to this paper should be made as follows: Bostrom, R.P., Gupta, S. and Hill, J.R. (2008) Peer-to-peer technology in collaborative learning networks: applications and research issues, Int. J. Knowledge and Learning, Vol. 4, No. 1, pp.3657. Biographical notes: Bob Bostrom is the L. Edmund Rast Professor of Business at the University of Georgia, USA. He teaches in the area of Management Information Systems (MIS). He is also the President of Bostrom & Associates, a training and consulting company focusing on facilitation and the effective integration of people and technology. Bostrom holds a BA in Chemistry and an MBA from Michigan State University, an MS in Computer Science from SUNY at Albany, and a PhD in MIS from the University of Minnesota. Besides numerous publications in leading academic and practitioner journals, he has extensive consulting and training experience in the areas of MIS management and design, organisational development, leadership, facilitation, business process management and digital collaboration. His current research interests are focused on high-performing individuals, facilitation, business process management systems, digital collaboration, technology-supported learning and the effective design of organisations via integrating human and technological components. Saurabh Gupta is an Assistant Professor with the Coggin School of Business, University of North Florida, USA. He teaches in the area of Management Information Systems (MIS). He has work experience in the field of knowledge management, system design and enterprise resource planning implementation. Gupta holds a PhD from the University of Georgia, a BBA from Gujarat University, India, a Post Graduate Diploma in Management from Nirma Institute of Management, India and an MBA from the University of Georgia. His current research interests are end-user training, technology-supported learning, knowledge management and the adoption of complex technology. His research has been published in numerous conference proceedings and the International Journal of Knowledge and Learning, Knowledge Management Research & Practice, Encyclopedia on E-collaboration and Business Education Forum. Janette R. Hill is a Professor in the College of Education at the University of Georgia, USA. Prior to coming to the University of Georgia, she held academic appointments at the University of Northern Colorado and Georgia State University. Her research interests include community building, resource-based learning and web-based learning environments. Dr. Hill holds a Masters degree in Library and Information Science and a doctoral degree in Instructional Systems Design, both from Florida State University. Her articles have appeared in research and professional publications including Educational Technology Research and Development and The Internet and Higher Education. 1 Introduction From a technology perspective, the Client/Server (C/S) architecture has dominated the thinking in collaborative learning research and practice. Such focus on a single class of technology may be limiting, thus, creating missed opportunities. As an alternative technology, Peer-to-Peer (P2P) technology offers some interesting benefits and 38 R.P. Bostrom, S. Gupta and J.R. Hill challenges. P2P technology is not only the fastest growing internet technology, but also a variety of good P2P applications already exists and others are emerging. P2P applications such as Seti@home and Napster aggregated literally millions of computers/peers together to create a resource that was undeniably unique in its power and capabilities. Can we create the same kind of applications in the learning area? In spite of this P2P growth, much of P2P research and literature has focused only on explaining the technology instead of focusing on software applications. This is true across sectors, including education (Fletcher, 2004; Kook, 2001), business (Gartner, 2004; Kini, 2002) and computer science (Fattah, 2002; Lytras et al., 2003a). When applications are discussed they tend to focus on a single application (Curran, 2002; Leighton and Mldner, 2005). We are interested in exploring the potential of P2P technology for learning, particularly for developing Collaborative Learning (CL) capabilities. The purpose of this paper is to present a framework for describing different levels of CL in organisations and discuss the most relevant P2P applications at each level. P2P applications will be compared to C/S counterparts highlighting how the two types of systems might work together in CL networks. The paper starts with a discussion of collaborative learning networks, presenting a model for collaboration within this social network. This model is then used to compare P2P and C/S approaches to CL. We then present a framework describing the different levels of CL in organisations and discuss the most relevant P2P applications within each level. Research results, sample applications and cases are used to illustrate key points. Key research issues are identified throughout the paper. 2 Collaborative learning networks The education literature defines CL as instructional methods that encourage students/people to work together to accomplish shared learning outcomes, beneficial to all. It involves social (interpersonal) processes where participants help each other to understand as well as encourage each other to work hard to promote learning (Allee, 2000). CL procedures have been found to be more effective than traditional instructional methods in promoting student learning and academic achievement (Johnson et al., 1981; 1991; Slavin et al., 1985). In a comparison of CL vis--vis traditional classroom learning, researchers found that a collaborative approach increases student involvement with the course (Collier, 1980; Cooper et al., 1990) as well as with each other (Cooper et al., 1990), increases the level of critical and active thinking (Bligh, 1972; McKeackie, 1980), promotes problem-solving skills (Kulik and Kulik, 1979) and increases student satisfaction (Kulik and Kulik, 1979; Bligh, 1972). More recent analysis (Lou et al., 1996; Rohrbeck et al., 2003) also support these outcomes. Most of the research in the education literature has concentrated on face-to-face forms of collaboration in small teams, using minimal technology to support them. In business, we are seeing more use of CL in teams but primarily in virtual teams. There is also a tremendous growth in use of community of practices in businesses to promote learning. Similar trends are appearing in education with growth of distance learning and the use learning communities (see Moore and Anderson (2003), for an overview of distance education initiatives). Peer-to-peer technology in collaborative learning networks 39 Technology, especially computer networks, is enabling major new ways to implement CL. We have witnessed the evolution of the user of technology-mediated learning from a single person to an interacting dyad or group, from a group of people to a community with dynamic membership, from a community to an entire organisation, and from a signal organisation to multiple organisations (DeSanctis, 2006). Thus, we can no longer limit our frame of CL to traditional classrooms using small teams. We need focus on how learning takes place in different Collaborative Learning Networks (CLN): dyad, group, community of practice, organisation, and interorganisational. Learning networks assume two or more people linked together (i.e., network nodes) to promote learning by providing opportunities for seeking and providing information and knowledge, and forming relationships that support learning. Adding the word collaborative in front implies some form of shared learning outcomes. Besides making new forms of CLN possible, Information and Communication Technologies (ICT) afford different levels and types of support for learning networks. Current CLN are dominated by C/S applications. A number of P2P applications are making large impacts on different CLN. However, there has been little research on what makes a good P2P application or what questions instructor/designer/purchaser should ask to judge if a P2P application is appropriate for their organisations learning needs. 3 Collaborative learning network node In a business, CL focuses on identifying and leveraging the collective knowledge/learning in an organisation to help the organisation compete. Competitive advantage comes from building capability faster than competitors. Capability develops from organisational members exchange of knowledge to establish the right direction, overcome challenges/problems, execute processes effectively, and learn. Thus, collaboration generates new capability, through knowledge sharing and learning, and is a key to accelerating performance, and in turn, competitive advantage. This same argument would apply to academic organisations if we think about competing in terms of accomplishing teaching, research and service goals. The core of CLN is networked members sharing knowledge/learning. Thus, let us focus on how a member seeks or provides knowledge within a network. Members can exchange knowledge with one another directly through the medium of shared knowledge space or through conversation. Schrages (1997) collaboration model looks at shared knowledge spaces as a new dimension to conversation, a dimension embracing symbolic representation, manipulation and memory facilitating the capturing of the context. The shared space acts as a common repository for knowledge storage. Changing the conversation can lead to changes in the shared space and visa versa. Symbols, ideas, processes, sketches, audio and video files, words, etc., can be put in the shared space to be manipulated to build new meanings. The model emphasises the need for collaboration beyond pure communication for increased CL effectiveness and efficiency. Knowledge is learning applied productively. The activities usually involved in CL process include: Knowledge Creation (KC) involves developing new content or replacing existing content within CLNs knowledge. 40 R.P. Bostrom, S. Gupta and J.R. Hill Knowledge Storage (KS), also referred to as organisational memory, constitutes an important aspect of effective CLN because empirical studies have shown organisations lose track of the acquired knowledge. Knowledge Retrieval and Transfer/Distribution (KT) is getting the right information to the right person at the right time. Knowledge Application (KA) is important because the application of the knowledge rather than in the knowledge itself is what is of value (Alavi and Leidner, 2001). The entire process of CL in a network is cyclic, where knowledge application can lead to further knowledge creation and storage, thus repeating the cycle. We have mapped these activities into Schrages collaboration model (see Figure 1). Knowledge is applied by people, and may have been accessed from a shared space or through conversation. Knowledge is created by people during conversation or via capturing knowledge directly into a shared space. Figure 1 makes clear that KS can reside both in individuals and shared spaces. The primary outcome of CLN is for members to share their knowledge/learning with relevant others. A CLN does this by providing the capability to take individual expertise/KS and aggregate (shared space) and share it through conversation or retrieval from a shared space. Figure 1 Collaborative learning network model Shared Space [KS]ConversationKC/KTKC/KTKC/KTReceiver/Sender Receiver/SenderKA KA[KS]KC/KTKC/KT[KS]Source: Adapted from Schrage (1997) CLN technology can be use to support any of the CL activities. For example, expert locator software allows faster access to knowledge sources to initiate a conversation to discover relevant knowledge, thus, improving knowledge transfer. The conversation could take place using audio or text-chat features in instant messaging software. Knowledge spaces/storages are digital repositories that people can search. The model also captures time-space dimensions of CLN. Synchronous collaboration allows for real-time audio/video and text-chat conversations, in co-located or distributed modes, and simultaneous access to shared spaces such as co-editing of documents; while asynchronous collaboration allows for access to a shared space anytime from anyplace. An example P2P application that illustrates this model is Groove. Groove is offered by Groove Networks which was recently purchased by Microsoft. Groove is now one of the tools provided in Office 2007. At the heart of Groove is a shared space. A user creates a shared space and invites other people into it. From the moment the invitation is accepted, Groove keeps synchronised copies of the shared space on each participants computer, incrementally updating whenever any member updates a document. It keeps track of all the collaboration taking place though the shared space thereby enhancing the teams ability to interact with each other. Groove offers both synchronous and Peer-to-peer technology in collaborative learning networks 41 asynchronous tools for communication, although the asynchronous tools are better developed. It also offers an application development platform that can be used to customise the functionality of each space. 4 Collaborative learning networks: peer-to-peer versus client/server applications At the most basic level, P2P is simply one computer node talking directly to another without any intermediary (Kini, 2002). Thus, P2P is a type of network in which each workstation has equivalent responsibilities. This differs from C/S architecture in which one computer (server) is dedicated to serving the others (clients). Communication in this scenario exists only between nodes and server, and no direct communication exists between nodes. P2P networks are based on the premise that better utilisation of resources (data, processing capacity, etc.) is achieved when all nodes are peers instead of relying on a central server (see Schoder and Fischbach (2003) for an overview of the history peer-to-peer computing). P2P applications are broadly characterised by Fattah (2002) into passive (utilisation of idle computing resources) and active (system is used to accomplish a task). Fattah further breaks down applications into four types shown in Table 1. We have also put in another taxonomy found in Fletcher (2004) to illustrate that most classifications can be mapped into the Fattah classification. The primary difference between active and passive applications is in the resources being shared on the network. Active applications are primarily sharing data while passive applications are sharing hardware resources such as processing cycles or storage. An example of passive system, that shares processing cycles, is the SETI@home, a project launched at the University of California at Berkeley. It uses internet-connected computers in the search for extraterrestrial intelligence. Anyone who has an internet connection and some spare processing cycles can participate by running a free P2P program that analyses radio telescope data. As of January 2008, more than five million people have signed up. In a CLN environment, the focus is on performance and learning, thus, active applications dominate. Napster and Gnutella, P2P file sharing programs, are probably the most famous examples of active applications because of all the legal policies that surfaced when they were implemented. Another example of active P2P collaboration application is the Groove system described above. Other P2P applications let users of different applications tie those applications together to pass along relevant information, while the document creator maintains ownership of the documents, e.g., NextPage. A quote from Andrew Mahon, director of strategic marketing for Groove networks, further illustrates the differences between P2P and C/S models: People create knowledge and they store it on their desktops.. It would be nice if they would publish it to a central location, the way client/server knowledge management tools are supposed to work, but people are lazy. P2P solutions allow people to look around and find the knowledge. (Kini, 2002) These differences are even easier to see when P2P and C/S models are mapped to the CL process as shown in Table 2. With C/S technology, the transfer of knowledge involves the creators and the receivers action in terms of transferring and fetching data to/from the server respectively. With P2P technology, the synchronisation of the shared space is 42 R.P. Bostrom, S. Gupta and J.R. Hill handled by the application. From the user view, they are simply putting and receiving documents in folders on their desktops. P2P combines the storage and transferring processes in the CL process, rather than going through the additional layer of the server. Additionally, the P2P shared spaces usually allow for co-editing, co-browsing and other functions to happen in real time. Table 1 P2P applications classification Fattah (2002) classification Fletcher (2004) Definition Example applications User collaboration Multiple peer/ collaboration peer Systems that provide users the ability to form groups and communities, both inside and outside the organisation Napster (file sharing) Groove (workspaces and communication) XBOX (gaming) Active Sharing data/information/ knowledge Application interaction Systems that help users of different applications tie them together to share relevant information while maintaining ownership NextPage (unstructured data, with centralised index) Resource utilisation Systems that allow users to tie all the resources of their systems to satisfy infrastructural needs Mojo Nation (bandwidth pooling) Passive Pooling hardware resources: processor, storage, bandwidth Super/Grid computing Distributed peer Systems that harness the computing power of distributed networked computers to produce virtual super computers Seti@home (pooling processing power of idle computers) Table 2 C/S compared to P2P in the KM process (see online version for colours) Activities Technology Creation (KC) Storage (KS) Retrieving/ Transferring (KT) Application (KA) Client/Server On client (creator) On server On server On client (receiver) Creator transfers data to server Receiver fetches data from server P2P On client (creator) Once initiated, the system transfers data between clients On client (receiver) The major inherent weakness of C/S application is that a central server can be a bottleneck in terms of the applications performance, scalability and reliability. For example, the availability of any C/S application is based on the availability of the central server. If server is down, you cannot work. This is not true for P2P applications since the shared space is on my computer/peer, and thus, I can work on shared space anytime. After working, offline, once I connect to the network, my changes to the shared space will be replicated to other peers/computers that have access to this shared space. In addition, if one peer/computer in network is down, I can always pick up changes from other peer that is active and has access to the shared space. Peer-to-peer technology in collaborative learning networks 43 It is this ability to more closely implement the collaboration model (Figure 1), especially the face-to-face conventions of human communication, that make P2P applications very useful for CL in many situations. The P2P environment facilitates formal and informal information exchange. As more learners/peers join the network, opportunities for more information to be stored, accessed, exchanged, and learned increase. It is important to note that human behaviour, not technology is the key CL challenge (Tiwana, 1999). If people will not share knowledge, there is no collaborative learning. Although in this paper we are focusing on technology, we want to make it very clear that successful CL efforts need to take a socio-technical approach integrating technology, process, and people issues. Besides learner motivation, another major people issue is building a learning team/community. Research indicates that a sense of community is beneficial to successful CL (Hill et al., 2002). Hill (2002) provides some best practices for building community in web-based learning environments. 5 Different collaborative learning networks Before discussing different levels of collaborative learning networks within an organisation in general, we will illustrate them by describing an academic environment in which one of the authors has been involved. The environment is the Terry College of Business MBA programme, University of Georgia (UGA), created for the IBM PricewaterhouseCoopers (IBM PwC) North American Consulting Group. IBM PwCs primary goals were consultant retention and development through a flexible and customised MBA programme. The Terry College was interested in developing a strong position in the executive education market and an e-learning infrastructure. The programme is a combination of face-to-face classroom sessions and distance learning. Small, four to five people virtual learning teams are used as a key learning vehicle in the programme. The two-year MBA programme was launched in October 1998. The programme has been a huge success for both IBM PwC and UGA. US News and World Report rated the programme one of the top online graduate programmes (see Special Report: E-Learning, 15 October 2001. For a detail write-up on the development and implementation of this programme see Bostrom et al. (2002)). One of core technologies used in this programme was a Course Management System (CMS), first LearningSpace and currently Blackboard. One of the biggest problems encountered using a CMS was its sole focus on the class versus the larger MBA programme. Most CMS allow for limited programme view or none at all. While each class is important for the student, it is the programme or how each class fits with the others that make an MBA degree valuable. As a solution, another CMS course was created to provide this programme view, but this solution still lacked many important features such as an easy way for the students to see an overall picture of what was due for them in any one of their classes. This problem highlights the point that multiple CLNs are needed to support different organisational levels and that these networks need to be seamlessly connected. Most academic organisations would have the six levels shown in Figure 2 and described below: 1 Individual-dyadic tools to support the most basic form of collaboration within an organisation occurs at an individual-dyadic level 44 R.P. Bostrom, S. Gupta and J.R. Hill 2 Team/Group tools necessary for student teams geographically spread out or co-located to meet, work on assignments and collaboratively learn together 3 Course/Class the resources and tools to teach/take a particular course: course design, assignments, discussions, grading, etc. 4 Programme the management and coordination of multiple courses: integrated planning, scheduling and resource allocation, programme discussions, etc. 5 Organisational the management of multiple programmes: programmes integration and management; student registration, tracking, etc.; faculty support and collaboration; etc. 6 Inter-organisational the tools to access resources and collaborate that support learning within multiple organisations. Figure 2 Levels of collaborative learning networks (see online version for colours) Individualnetwork nodeCommunity ofpracticeCourse/ClassTeam/ProjectOrganisation College/AcademicentityProgrammeCourse/ClassTeam/ProjectOrganisation B Academic entity AInterorganisationalDyadcollaboration Peer-to-peer technology in collaborative learning networks 45 Using the Terry-IBM MBA programme as an example, students work individually and in teams within a given course. Technology was needed to support both individual-dyadic, team and course levels. We also needed support for overall management of the programme in terms of things such as integrated scheduling and programme-wide discussions. Similarly, from an organisational perspective, it would be useful to have technology support the management and integration of different learning programmes. For example, the IBM Consulting MBA is one of five MBA programmes in the Terry College. Terry continually has problems with scheduling, resource allocation, sharing information, etc., between these programmes that technology could support. In addition, technology was needed to support the management and coordination of the IBM PwC MBA programme by UGA and PwC. The differences between Learning Management Systems (LMS), Learning Content Management Systems (LCS) and CMS are highlighted using the level model in Figure 2. A LCS or CMS usually focuses on course and individual-team levels, while LMS tend to provide some support for all levels but focuses on upper levels, programme-organisational. Most CMS/LCS do not provide good team support tools and do not support programme and organisational levels. IBM PwC MBA programme created some limited ways to support programme and organisational levels as discussed above. However, the programme could have used much better support at these levels. In addition, the programme had to add a number of technology tools to support dyadic and teamwork levels. Obviously, these tools were not seamlessly linked. What is needed is technology that seamlessly links these CLN. The issue of learning content available in a CLN is very important to a organisations e-Learning strategy. When we started IBM PwC MBA programme, not a lot of content was available so faculty developed a lot of content on their own and incorporated pieces developed by others. However, today there is a lot more electronic content available to plug into all CLN levels. The trend is towards the development of learning objects and complete courses that use these objects. The objects are reusable and easily moved between different or within the same technologies and vendors because of standards promoting interoperability. For example, we are now looking at buying learning objects and complete courses to use, much like we have done with textbooks for ages. There are now companies that sell core MBA courses. Clearly, we need to develop strategies for acquiring, developing and managing learning content. Many organisations are struggling with this content issue including most universities. P2P and C/S provide two very different approaches to this content issue. C/S keeps all relevant content on server and it is up to the user to upload and download content. In P2P applications, content relevant to the user would be kept on their machine and duplicated on other users machines who found content relevant. One of the P2P applications we will discuss later, LionShare, addresses this content issue. It is an innovative effort to facilitate legitimate sharing of digital content among individuals and educational organisations around the world. Merlot is a client/server application that provides similar functionality for sharing digital content. 46 R.P. Bostrom, S. Gupta and J.R. Hill 6 Collaborative learning networks typology Although we could not find any typologies of CLN, the literature does provide some guidance via knowledge networks classifications (Clark, 1998, Lytras et al., 2003b; Mentzas et al., 2001) and collaboration models (Allee, 2000; Creech and Willard, 2001). Based on these typologies, we developed a comprehensive framework of CLN that includes five different organisational levels: individual-dyadic, project/team, community of interest/practice, organisational, and inter-organisational (see Table 3). Each of these levels serves a different purpose in the organisation and presents a different CLN. Any organisation may have more than one CLN operating at a given level. For example, in our educational example (see Figure 2), we outlined six levels, but using the generalised typology (Table 3), we would classify both course and programme levels as communities of practice. Table 3 captures examples of content contained in network, sample P2P applications that have been used or developed in educational environments, and duration that applications and content are generally used. The most basic form of collaboration within an organisation occurs at an individual-dyadic level. The value generated at this level is the knowledge/learning generated through the collaboration process shown in Figure 1. There are various P2P software applications at this level, with the most notable being instant messaging. Teams are formed to work together to accomplish shared learning outcomes. Technology helps achieve these outcomes more quickly through the use of interactive shared spaces. For example, Groove implements this concept by helping the users to share plans, schedules, documents and discussions in a shared project space. Communities of practice within or between organisation(s) are similar to teams except they usually have more members that are loosely coupled. Communities essentially share and manage information in a particular area for the purpose of joint learning. Technologies used for communities are similar to those used for teams/projects. Over a period of time organisations capture a lot of knowledge in the form of documents, rules, policies, practices, insights, etc.; but most of this is stored at individual and team levels. Organisations need tools to help them store and transfer this knowledge in a way that it can be easily retrieved and shared across the organisation. P2P tools like NextPage help catalog documents on individual computers in an organisation so that they can be shared across the organisation. The C/S response in this area is an organisational or enterprise portal. Interorganisational CL within the supply/value chain has become a major focus of business organisations. Although collaboration between organisations could occur at any of the levels outlined (individual, cross-organisational team, etc.) using tools outlined in the Table, specific inter-organisational P2P applications have just started to emerge. For example, LOCKSS (Lots of Copies Keep Stuff Safe) is a P2P system where libraries work together to ensure that online journals and web documents are preserved permanently to guarantee their availability. The following sections highlight specific P2P applications in more depth within each level. Peer-to-peer technology in collaborative learning networks 47 Table 3 Levels of collaborative learning networks (see online version for colours) Organisational level Examples of content Duration of context P2P technology/products Individual-dyadic Presentation Meeting Dialogue Minutes, hours Instant Messaging Voice over IP Messenger Skype Groove Helpmate Onobee Edutella Project/Team Plans Schedules Working drafts Discussions Days, weeks, months Interactive workspaces Groove Helpmate Edutella Community of interest/practice/ department Relevant content to community Discussions References Norms and ground rules Days, weeks, months, years Interactive workspaces LionShare Groove/Sharepoint Edutella Organisational Workflow Applications Policies and practices Templates Documents and reports Analyses Weeks, months, years Document sharing Indexing LOCKSS NextPage Interorganisational Marketing Advertising Retailing Trading Weeks, months, years Content sharing Indexing LOCKSS LionShare 7 Individual-dyad level At this level, we will discuss two applications: personal knowledge management and dyadic communication. In collaborative learning networks, each node is a person. The better one can organise and access their personal knowledge, the better able they will be able to contribute to the collaborative network. P2P applications can be used for personal knowledge management. Personal knowledge management involves having a process to store and access knowledge documents anytime and anyplace. Knowledge workers and students today work at multiple locations and on multiple projects. The need to access documents from different computers in different locations is increasing. Two of 48 R.P. Bostrom, S. Gupta and J.R. Hill the authors of this paper extensively use Groove to manage their own personal knowledge-bases, spaces that are not shared. This allows us to work on documents when not connected to a network and access all our knowledge-bases from any of our computers. We also have the ability to invite others to share these spaces if desired. Research is needed to examine the impact of such P2P tools on personal productivity. P2P applications are also useful for dyadic communication. Researchers have reported that Instant Messaging (IM) is being used for a variety of activities, from mentoring (Dieterle, 2005) to creating virtual hallways for participants in online courses (Nicholson, 2002). While some have raised concerns over the use of IM (see, for example, Texley, 2005), others have sought to understand how it might best be used in an educational context. DeGennaro (2005) contends that IM enables participants instant access to others (instructor-student, student-student), not only enabling connections to be established, but also to further the technological fluency of those engaged in the activity. Other researchers are exploring how IM might be used in more traditional classroom contexts. For example, Kinzie et al. (2005) conducted a study of students using IM during face-to-face lectures. While the instructors and students reported that the use of IM was somewhat disruptive, the researchers concluded that using IM in other ways (e.g., applications of multiple sequential (rather than simultaneous) tasks during classroom instruction) might make IM a useful tool in the classroom. More research is needed to fully understand the implications and applications of IM for educational purposes. 8 Learning team/project There are a number of successful learning team P2P applications, such as Groove. These have been written up in the practitioner literature and we have experienced many successes ourselves over the last three years (for examples see Bostrom et al., 2003; Curran, 2002; Hofmann, 2002; Groove website).1 Most of these cases find the following benefits of P2P learning team applications: work in different time/place modes, work disconnected from network, ease of use and access to people, enhanced communication and participation, enhanced process structuring, and a common place for information that can be access quickly and easily exchanged. Instead of focusing on one of these cases, we felt that it was important to examine the bigger picture via reporting some recent research we were involved in on the major users of team tools, Virtual Teams (VT) (Thomas, 2005). Although these teams were not formal learning teams, a great deal of informal learning went on in the teams. In addition, our experiences with formal learning teams would suggest that results of this study would be applicable to them. The study involved interviews with 13 practicing VT leaders across 20 organisations, including more than half of the top outsourcing firms according to Information Week. They reported incidents from 30 projects spanning the breadth of the Information System project domain from analysis/assessment and new systems design to larger BPR/change management efforts or ERP implementations. Many of the projects involved outsourcing or off-shoring. The leaders reported their teams using median of 12.5 Collaboration Technologies (CTs) each (minimum of 7 and a maximum of 18). This is a very surprising finding, considering that most prior research has examined only one or a few technologies at a time. Three CTs (phone, e-mail and audio conferencing) were used in 100% of the Peer-to-peer technology in collaborative learning networks 49 projects. The other most common tools reported in at least 20 projects (66%) were project management tools, development environment tools, document versioning tools, file repositories, instant messaging, and teamspaces. These numbers would be higher than numbers in many other business and academic areas due to tasks involved; information systems teams use additional technology in their work. For example, in the UGA MBA educational example described above, most of the virtual teams used seven CTs: phone, e-mail, audio conferencing, course management system, team workspace, instant messenger, and content management system. Many of these tools were P2P based, e.g., instant messaging and some of the teamspaces, others were C/S based, e.g., project management and file repositories. The leaders indicated that integration or interoperability across systems and across different versions of same software was a major problem, along with reliability, constant availability and usability or ease of use. These are major issues that CT developers and researchers need to address. For collaborative learning networks to be truly effective, integrated technological infrastructures need to be developed. These integrated solutions are not available yet! However, there has been some excellent research in the educational area on integrating educational applications which will be discussed later (Ternier et al., 2005; Leighton and Mldner, 2005). 9 Cross organisational community of practice The LionShare P2P project,2 started by Penn State University, is an innovative effort to facilitate legitimate sharing of digital content (documents, videos, photos, sound, etc.) among individuals and educational organisations around the world. The system is designed to let an individual manage their personal files, and then make these files available throughout a P2P network. Many academics have hidden digital content repositories used for teaching and research stored on their networks or hard drives. The goal of LionShare is to open this content up via a search system so that a single query could reach all available repositories. LionShare provides academics tools for cataloging their own collections and then export those catalogs throughout academia. These cataloging structures are used to guide network searches. Of course, academics could just put links to their digital repositories on the web and let a search engine, such as Google, handle it all. However, this approach has a couple of downsides. First, it is the typical C/S approach we discussed earlier where the individual has to upload and download content from a server. Secondly, there are no easy ways to ask search engines very specific questions such as get me all the early photographs of computers developed during the 1960s and 1970s. Search engines do not handle metadata or catalog information well. The primary research question that the LionShare project addresses is: How can P2P systems be designed to best promote collaboration for teaching, learning, research, and outreach in the Higher Education environment? However, an application like LionShare may also help facilitate community building amongst various subsets of the larger academic community. As noted earlier, more exploration is needed to fully understand the capabilities of specific P2P applications, for collaboration as well as community building. 50 R.P. Bostrom, S. Gupta and J.R. Hill 10 Organisational level Educational organisations are continually creating documents, such as curriculum proposals and budgets that need to examine by different areas within the organisation for development, approval or information sharing. Most of this document sharing is done through e-mail. You can talk to any member of an educational organisation and hear a story about how they have wasted hours working on the wrong document version, sent the wrong version out for review, or cannot find the most recent version of a document. The P2P application NextPage3 was created to help you deal with document sharing problems. NextPage allows users to continue using familiar tools on their desktops that give them the agility they need to function easily in their work world: personal computers with e-mail and Microsoft Office authoring applications. The NextPage service weaves a digital thread through important shared files, allowing users to track and manage them throughout the entire document life cycle. For example, a curriculum proposal creation would go like this in NextPage. Bob completes a draft proposal and e-mails the document to Janette. Janette makes edits to the document and sends it back. Bob is notified when Janette starts working on the document and when the new version arrives. Bob integrates Janettes edits into his version and sends out the newer version this time to Tom, Chris and Saurabh. They see the composite document as to Bob and Janette. All three make their edits and e-mail their documents back. Bob then creates a final version which is immediately viewable by all those involved in the curriculum development effort. Another organisational open source P2P application supports libraries. Libraries provide access to information and knowledge to current and future generations of readers. With evolution of the web, libraries know have to deal with electronic as well as physical archives. The changing nature of World Wide Web content is a fact of digital life that affects everyone but especially libraries. How can you find documents that were accessed through the publishers website when the publisher goes out of business? How can you ensure that published materials will always be found by interested (and authorised) readers? Ensuring continuous access to online journals and other web documents is the focus of a unique collaboration between Sun Microsystems Laboratories and Stanford University Library. The result of this collaboration is the P2P LOCKSS system, an exciting new data integrity and document protection solution. The goal of the LOCKSS project4 is to enable libraries to take custody of the material to which they subscribe electronically in the same way they do for paper and preserve it permanently. With a clever and simply to use polling system, the LOCKSS system permanently caches copies of online content enough copies to assure continuous access around the world. This helps ensure that published material will be available even if it is no longer available from the publisher. And when a copy of an online journal is misplaced or damaged, the LOCKSS system takes notice and replaces it. The concept behind the LOCKSS system is based on simple rules. Acquire lots of copies. Scatter them around the world to different P2P nodes. Lend or copy your copies when other libraries need them. And collaborate only with competent and trusted libraries. This design could not be accomplished in C/S application. More research is needed to fully explore the capabilities of a system like LOCKSS. Peer-to-peer technology in collaborative learning networks 51 11 Future research We outlined research issues in previous sections that applied to a specific collaboration level or issue being presented. In this section, we address research issues that apply to multiple collaboration levels. There is no formal research comparing P2P tools versus C/S tools at the various levels. The practitioner literature suggests that P2P applications are having their biggest impact and success at individual-dyadic and team levels, where C/S based tools dominate at other levels. This literature suggests that both C/S and P2P technologies have their advantages and are more suited to different levels. The business VT study, dicussed previously, showed that both C/S and P2P can co-exist and even might complement each other within a given level or across levels. This conclusion has also been supported in an educational setting (Ternier et al., 2005). More research is needed to understand their effectiveness within a level and how they can be integrated. Kini (2002) and Lytras et al. (2003a) outlined a set of models ranging from P2P to a combination of P2P and C/S. Different models could be applicable to different collaborative learning networks. Lytras et al. (2003a) take their P2P models and apply them in e-learning context creating taxonomy of P2P models for formal and informal e-learning situations. However, research cannot focus on a single level alone. Knowledge captured at various levels needs to flow across the levels to provide for a richer collaborative learning process. For example, team learning nuggets need to find their way to organisational level so other teams can benefit from the learning. Our VT research found very little knowledge sharing across teams primarily because of integration problems mentioned above. Research is needed to find out how best knowledge can flow across levels and how different combinations of technologies can facilitate this flow. For example, Groove (P2P, team level) has a linkage with Microsoft Sharepoint software (C/S, organisational level). Groove also links to the individual-level Microsoft Office tools and PC file systems. We need to make both collaborating and contributing to the organisational knowledge-base easy. A good example of the type of research needed in interoperability or integration area is the work done by Ternier et al. (2005). They report their experiences in bridging learning object repositories, client-server applications, and P2P applications. More specifically, they developed bridges between the ARIADNE Knowledge Pool System, a distributed client/server based learning object repository with applications from Edutella P2P learning network. Their research demonstrated the feasibility of making both of these systems interoperable and showed that both approaches are not only compatible but also complementary. Our experience and research would agree that P2P and C/S applications can complement each other. What we need is better interoperability between systems. In the education area, the most ambitious attempt to create interoperability between applications is found in the P2P based prototype system called APEX which addresses the integration issue at the architecture level (Leighton and Mldner, 2005). APEX is a P2P architecture designed to support the integration of distributed educational applications. Components, such as instant messaging or scheduling software, can be easily integrated and supported in APEX. APEX provides a foundation for integrating applications to suit a given organisations learning needs. 52 R.P. Bostrom, S. Gupta and J.R. Hill Most of the research to date on P2P applications has focused on the individual-dyadic, project/team collaboration and community of practice levels. The community of practice research has focused on investigated classes as communities. Clearing missing is research on higher collaboration levels: other community of practices, such as academic programmes; organisations; and inter-organisational efforts (see Figure 2 and Table 3). There are many exciting initiatives to investigate but little has been done. Good examples of the type of research that needs to be done can be found in Alavi and Gallupe (2003) (present five successful cases) and Bostrom et al. (2003) (one in-depth case). From a research perspective, it should be clear from our discussion of the different types or levels of collaborative learning networks that these different types are not distinct levels of analysis. Instead, these different types are inherently intertwined networks in which people interact with one another, and distinctions between levels can be arbitrary at times. As examples, individuals could be part of multiple team and community of practice networks. Team and community of practice networks may apply to the same context such as our class example discussed previously (see Figure 2). Communities of practice may have members from multiple organisations and may operate outside of any participating organisational boundaries. The researcher has a number of challenges such as which network to focus on, need to incorporate multi-level data into studies, and bounding those networks involved in a meaningful way. Traditionally, researchers have set boundaries based on formal membership such as formal organisational entity or membership in professional organisation or class. Though still relevant such boundary setting is limited in a dynamic world where communities are defined by many attributes other than formal membership. Since software applications tend to support one or two levels, most settings are going to have multiple applications. Thus, like networks, researchers cannot just focus on one technology, which is the norm in past research, but must give serious consideration to which applications to include in a study. 12 Problems with peer-to-peer applications We have highlighted the advantages P2P applications in the above examples. It is important to also consider the limitations. There are three major limitations of current P2P architectures compared to the C/S architectures: 1 authentication 2 searching/accessing 3 technological issues such as network control, security, protocol interoperability, meta-data creation and cost sharing. P2P tools, such as Groove, are addressing 1 and 3 to some extent through integrating P2P with some C/S capabilities. Though some work has been done on the technology side of searching data in P2P systems, e.g., LionShare Project discussed previously, more research is needed on both behavioural and technological aspects of point 2, searching/accessing. The Semantic web, discussed in the next section, is the major Peer-to-peer technology in collaborative learning networks 53 research and development effort aimed at improving searching/accessing. Most of the academic research to date has focused on these three limitations especially #3. For a detailed discussion of these issues, see Fattah (2002). 13 Future of peer-to-peer applications In the future, many people believe that P2P networks and applications will be the norm, and we may look back at todays client/server systems as more of a transitory technology. Although we do not see this happening in near future, the growth and use of P2P applications will increase. There are some significant trends currently happening that are fueling this growth: P2P architectures, P2P development environments, the growth of Grid computing, and the Semantic Web. In this section, we will briefly overview these trends and their relationship to P2P applications. A pure P2P network, or sometimes referred to as fully decentralised P2P network, is the one we have focused on in this paper in which there only peers/clients with equal privileges and there are no servers or supernodes in the network. However, there are variations of this basic architecture that have emerged. Lytras et al. (2003a) describe three types of P2P architectures: fully decentralised, hybrid and partial decentralised. Hybrid P2P networks combine P2P and client/server architectures. The most common case of hybrid is where there is one supernode/server which is responsible for the overall management of the network. The major task of super node is to maintain indexes that keep track of resources on each node/peer. Many of current applications referred to as P2P, such as Napster and most instant messaging systems, use this hybrid design. In partial decentralised architectures, we add more supernodes and distinguish between supernodes and nodes according to the available resources on each node. Lytras et al. (2003a) take their P2P classification structure and map it to informal and formal knowledge networks creating six clusters of P2P applications. We could do a similar mapping with our collaborative learning network levels (see Table 3). The bottom line is that P2P architectures are evolving, creating new and exciting environments for creating P2P collaborative learning applications. P2P development environments or platforms are becoming common place making it easier to create P2P applications. For example, two major vendors in software development tools provide environments: Sun Microsystems Project JXTA5 and Microsoft Windows P2P platform.6 APEX system, using the JXTA platform, has developed a P2P architecture to which educational software components, such as an instant messenger, can be easily be added to meet the learning needs of the organisation. APEX can be viewed as a special development platform for an educational environment. Groove, discussed previously as an application, also provides a development platform for developing P2P applications (Edwards, 2002). Mircosofts recent purchase of Groove and the integration of Groove in Office 2007 further shows their commitment to P2P applications. Recently there have been a number of articles suggesting a synergy between P2P and Grid Computing (Talia and Trunfio, 2003). A great introduction to Grid computing can be found at Grid Caf.7 Grid Caf states that a: 54 R.P. Bostrom, S. Gupta and J.R. Hill Grid is a service for sharing computer power and data storage capacity over the Internet. The Grid goes well beyond simple communication between computers and aims ultimately to turn the global network of computers into one vast computational resource. Passive P2P applications (see Table 1), such as Seti@home, are considered examples of a Grid-based system. Grid computing is currently in a prototyping phase with massive amounts of research and development dollars fueling its development. All indications are that both active and passive P2P applications and the P2P network technology will be an important resource within the Grid Computing infrastructure. Recently, a lot of research has been aimed at the Semantic Web. A subset of this research has focus on combining the benefits of Semantic web and P2P technologies (Gmez-Prez and Euzenat, 2005). The Semantic Web is an extension of the current web in which information is given well-defined meaning, better enabling computers and people to work in cooperation. It is based on the idea of having data on the web defined and linked in meaningful ways such that it can be used for more effective discovery, automation, integration, and reuse across various applications. Ontologies provide the mechanism for capturing meaning in content on the Semantic Web. These ontologies provide machine-understandable, shared conceptualisations of the respective domains of interest within collaborative learning network, while P2P systems are a means for communities to establish communication among their members. In contrast to most existing P2P implementations, ontology-based P2P systems will open up new possibilities with richer, potentially more useful descriptions of peers and shared knowledge. The more meaning that is captured in the network, the richer the learning opportunities. P2P applications will play a major role in the emerging Semantic Web. There are a lot of good P2P applications out there today. The trends highlighted above make it clear that there are many P2P applications waiting out in the wings, to be the next Napster or Skype of learning. Each of these trends represents a rich area of research related to educational P2P applications. 14 Conclusion Let us start this conclusion with two sentences from the Introduction: P2P systems such as Seti@home and Napster aggregated literally millions of computers/peers together to create a resource that was undeniably unique in its power and capabilities. Can we create the same kind of applications in the learning area? We have shown in this paper that P2P collaborative learning systems can facilitate entirely new ways of working within and among learning organisations. There are a number of good P2P applications out there and more on the horizon. There has been little research on what makes a good P2P application or what questions an application designer/purchaser/trainer should ask to judge if a P2P application is appropriate for the organisations learning needs. We need to start focusing research on P2P applications to provide guidance to learning system developers, purchasers and users. In this paper, we have provided direction for research and practice in this area. Peer-to-peer technology in collaborative learning networks 55 References Alavi, M. and Gallupe, R.B. (2003) Using information technology in learning: case studies in business and management education programs, Academy of Management Learning & Education, Vol. 2, pp.139153. Alavi, M. and Leidner, D. (2001) Review: knowledge management and knowledge management systems: conceptual foundations and research issues, MIS Quarterly, Vol. 25, pp.107136. Allee, V. (2000) Knowledge networks and communities of practice, OD Practitioner, Journal of the Organization Development Network, Vol. 32, vol32n4/knowledgenets.html (accessed 20 November 2002). Bligh, D.A. (1972) Whats the Use of Lectures?, Harmondsworth, England: Penguin. Bostrom, R.P., Kadlec, C. and Thomas, D. (2002) Implementation and use of collaboration technology in e-learning: the case of a joint university-corporate MBA, in B.E. Munkvold (Ed.) Implementing Collaboration Technologies in Industry: Case Examples and Lessons Learned, London: Springer. Bostrom, R.P., Kadlec, C. and Thomas, D. (2003) Implementing and use of collaboration technology in e-learning: the case of a joint university-corporate MBA, in B.E. Munkvold (Ed.) Implementing Collaboration Technologies in Industry: Case Examples and Lessons Learned, London: Springer. Clark, H.C. (1998) Formal Knowledge Networks: A Study of Canadian Experiences, Winnipeg, Manitoba: International Institute of Sustainable Development, URL:// fkn.pdf (accessed 25 November 2002). Collier, K.G. (1980) Peer-group learning in higher education the development of higher-order skills, Studies in Higher Education, Vol. 5, pp.5562. Cooper, J., Prescott, S., Cock, L. and Smith, L. (1990) Cooperative learning and college instruction, Cooperative Learning Users Group, Dominguez Hills, CA: The California State University. Creech, H. and Willard, T. (2001) Strategic Intentions: Managing Knowledge Networks for Sustainable Development, Winnipeg, Manitoba: International Institute of Sustainable Development, (accessed 25 November 2002). Curran, K. (2002) Peer-to-peer networking collaboration within education, Journal of Educational Multimedia and Hypermedia, Vol. 11, pp.2130. Degennaro, D. (2005) Should we ban instant messaging in school?, Learning and Leading with Technology, Vol. 32, pp.68. Desanctis, G. (2006) Who is the user? Individuals, groups, communities, in P. Zang and D.F. Galletta (Eds.) Human-Computer Interaction and Management Information Systems Foundations: Advances in Management Information Systems, Armok, NY: M.E. Sharpe. Dieterle, E. (2005) Mentoring Alex Bick, Learning and Leading with Technology, Vol. 32, No. 23. Edwards, J. (2002) Peer-to-Peer Programming on Groove, Boston: Addison-Wesley. Fattah, H.M. (2002) P2P: How Peer-to-Peer Technology Is Revolutionizing the Way We Do Business, Chicago, IL: Dearborn Trade Pub. Fletcher, K.M. (2004) Peer-to-peer networks and opportunities for alignment of pedagogy and technology, AACE Journal, Vol. 12, pp.301313. Gartner (2004) Forecast: e-learning software, worldwide, 20022008, Gartner report, (Executive Summary), Gartner, Gmez-Prez, A. and Euzenat, J. (2005) The Semantic Web: Research and Applications, Heraklion, Crete, Greece: Springer. Hill, J.R. (2002) Strategies and techniques for community building in web-based learning environments, Journal of Computing in Higher Education, Vol. 14, pp.6786. 56 R.P. Bostrom, S. Gupta and J.R. Hill Hill, J.R., Raven, A. and Han, S. (2002) Connections in web-based learning environments: a research-based model for community building, Quarterly Review of Distance Education, Vol. 3, pp.383393. Hofmann, J. (2002) Peer-to-peer: the next hot trend in e-learning?, Learning Circuits. Johnson, D.W., Johnson, R.T. and Smith, K.A. (1991) Cooperative Learning: Increasing College Faculty Instructional Productivity, Washington, DC, School of Education and Human Development The George Washington University. Johnson, D.W., Maruyama, G., Johnson, R.T., Nelson, D. and Skon, N.L. (1981) Effects of cooperative, competitive, and individualistic goal structures on achievement: a meta-analysis, Psychological Bulletin, Vol. 89, pp.4762. Kini, R.B. (2002) Peer-to-peer technology: a technology reborn, Information Systems Management, Vol. 19, pp.7485. Kinzie, M.B., Whitaker, S.D. and Hofer, M.J. (2005) Instructional uses of Instant Messaging (IM) during classroom lectures, Educational Technology & Society, Vol. 8, pp.150160. Kook, J. (2001) The internet and peer-to-peer computer networking: the principal attributes of P2P learning, WebNet Journal: Internet Technologies, Applications & Issues, Vol. 3, pp.3944. Kulik, J.A. and Kulik, C.L.C. (1979) College teaching, in P.L. Peterson and H.J. Walberg (Eds.) Research on Teaching: Concepts, Findings, and Implications, Berkeley, CA: McCutcheon. Leighton, G. and Mldner, T. (2005) Applying peer-to-peer technology to the building of distributed educational systems, Journal of Interactive Learning Research, Vol. 16, pp.295315. Lou, Y., Abrami, P.C., Spence, J.C., Poulsen, C., Chanbers, B. and DApollonia, S. (1996) Within-class grouping: a meta-analysis, Review of Educational Research, Vol. 66, pp.423458. Lytras, M.D., Tsilira, A.A. and Themistocleous, M.G. (2003a) Peer-to-peer knowledge networks and e-learning clusters of applications: a conceptual and technological approach of potential business value, Americas Conference on Information Systems, Tampa, Florida. Lytras, M.D., Tsilira, A.A. and Themistocleous, M. (2003b) Technology classification framework for e-learning purposes from a knowledge management perspective, Americas Conference on Information Systems, Tampa, Florida. McKeackie, W.J. (1980) Learning, Cognition, and College Teaching, San Francisco, CA: Jossey-Bass. Mentzas, G., Apostolou, D., Young, R. and Abecker, A. (2001) Knowledge networking: a holistic solution for leveraging corporate knowledge, Journal of Knowledge Management, Vol. 5, pp.94107. Moore, M.G. and Anderson, W.G. (2003) Handbook of Distance Education, Mahwah, NJ: L. Erlbaum Associates. Nicholson, S. (2002) Socialization in the virtual hallway: instant messaging in the asynchronous web-based distance education classroom, Internet and Higher Education, Vol. 5, No. 4, pp.363372. Rohrbeck, C.A., Ginsburg-Block, M.D., Fantuzzo, J.W. and Miller, T.R. (2003) Peer-assisted learning interventions with elementary school students: a meta-analytic review, Journal of Educational Psychology, Vol. 95, pp.240257. Schoder, D. and Fischbach, K. (2003) Peer-to-peer prospects, Communications of ACM, Vol. 46, pp.2729. Schrage, M. (1997) Collaborative tools: a first look, in R.L. Ruggles (Ed.) Knowledge Management Tools, Butterworth-Heinemann. Slavin, R.E., Sharon, S., Kagan, S., Hertz Larzarawitz, R., Webb, C. and Schmuck, R. (1985) Learning to Cooperate, Cooperating to Learn, New York: Plenum Press. Talia, D. and Trunfio, P. (2003) Toward a synergy between P2P and grids, IEEE Internet Computing. Peer-to-peer technology in collaborative learning networks 57 Ternier, S., Duval, E. and Leuven, K.U. (2005) Peer-to-peer versus federated search: towards more interporable learning object repositories, World Conference on Educational Multimedia, Hypermedia and Telecommunications (EDMEDIA). Texley, S. (2005) Should we ban instant messaging in school?, Learning and Leading with Technology, Vol. 32, pp.68. Thomas, D.M. (2005) The IS team leader role in technology appropriation for effective IS project virtual teams, Unpublished dissertation, Athens, GA, University of Georgia. Tiwana, A. (1999) Knowledge Management Toolkit, The: Practical Techniques for Building a Knowledge Management System, Prentice Hall. Notes 1 2 3 4 5 6 7


View more >