An Explorative Case-Study of the use of PeerWise to Foster Student Centred, and Peer Supported, Learning in a First-Year Business Module

Peer based learning is not a new concept in business studies in higher education; however, the integration of technology enabled and asynchronous peer learning has limited reported use and even less evidence based evaluation. In this explorative case study, the online tool PeerWise was used to scaffold and support an asynchronous peer-learning environment for a group of 212 first year business studies students. Students were required to create, answer and rate multiple choice questions on topics aligned to their curriculum within the peer constructed PeerWise question database. While there was no statistically significant correlation between PeerWise engagement and final module exam performance, conversely, considerable positive changes in student motivation, self-understanding and reflective learning were observed, informed by thematic analysis. With these key findings in mind, a set of themed recommendations for practice are offered to support staff seeking to integrate PeerWise, or technology enhanced peer learning more generally, into their teaching and learning practice

An Explorative Case-Study of the use of PeerWise to Foster Student Centred, and Peer Supported, Learning in a First-Year Business Module

Peer based learning is not a new concept in business studies in higher education; however, the integration of technology enabled and asynchronous peer learning has limited reported use and even less evidence based evaluation. In this explorative case study, the online tool PeerWise was used to scaffold and support an asynchronous peer-learning environment for a group of 212 first year business studies students. Students were required to create, answer and rate multiple choice questions on topics aligned to their curriculum within the peer constructed PeerWise question database. While there was no statistically significant correlation between PeerWise engagement and final module exam performance, conversely, considerable positive changes in student motivation, self-understanding and reflective learning were observed, informed by thematic analysis. With these key findings in mind, a set of themed recommendations for practice are offered to support staff seeking to integrate PeerWise, or technology enhanced peer learning more generally, into their teaching and learning practice

Using Internet Geometry to Improve End-to-End Communication Performance

The Internet has been designed as a best-effort communication medium between its users, providing connectivity but optimizing little else. It does not guarantee good paths between two users: packets may take longer or more congested routes than necessary, they may be delayed by slow reaction to failures, there may even be no path between users. To obtain better paths, users can form routing overlay networks, which improve the performance of packet delivery by forwarding packets along links in self-constructed graphs. Routing overlays delegate the task of selecting paths to users, who can choose among a diversity of routes which are more reliable, less loaded, shorter or have higher bandwidth than those chosen by the underlying infrastructure. Although they offer improved communication performance, existing routing overlay networks are neither scalable nor fair: the cost of measuring and computing path performance metrics between participants is high (which limits the number of participants) and they lack robustness to misbehavior and selfishness (which could discourage the participation of nodes that are more likely to offer than to receive service). In this dissertation, I focus on finding low-latency paths using routing overlay networks. I support the following thesis: it is possible to make end-to-end communication between Internet users simultaneously faster, scalable, and fair, by relying solely on inherent properties of the Internet latency space. To prove this thesis, I take two complementary approaches. First, I perform an extensive measurement study in which I analyze, using real latency data sets, properties of the Internet latency space: the existence of triangle inequality violations (TIVs) (which expose detour paths: ''indirect'' one-hop paths that have lower round-trip latency than the ''direct'' default paths), the interaction between TIVs and network coordinate systems (which leads to scalable detour discovery), and the presence of mutual advantage (which makes fairness possible). Then, using the results of the measurement study, I design and build PeerWise, the first routing overlay network that reduces end-to-end latency between its participants and is both scalable and fair. I evaluate PeerWise using simulation and through a wide-area deployment on the PlanetLab testbed

Systems-compatible Incentives

Originally, the Internet was a technological playground, a collaborative endeavor among researchers who shared the common goal of achieving communication. Self-interest used not to be a concern, but the motivations of the Internet's participants have broadened. Today, the Internet consists of millions of commercial entities and nearly 2 billion users, who often have conflicting goals. For example, while Facebook gives users the illusion of access control, users do not have the ability to control how the personal data they upload is shared or sold by Facebook. Even in BitTorrent, where all users seemingly have the same motivation of downloading a file as quickly as possible, users can subvert the protocol to download more quickly without giving their fair share. These examples demonstrate that protocols that are merely technologically proficient are not enough. Successful networked systems must account for potentially competing interests. In this dissertation, I demonstrate how to build systems that give users incentives to follow the systems' protocols. To achieve incentive-compatible systems, I apply mechanisms from game theory and auction theory to protocol design. This approach has been considered in prior literature, but unfortunately has resulted in few real, deployed systems with incentives to cooperate. I identify the primary challenge in applying mechanism design and game theory to large-scale systems: the goals and assumptions of economic mechanisms often do not match those of networked systems. For example, while auction theory may assume a centralized clearing house, there is no analog in a decentralized system seeking to avoid single points of failure or centralized policies. Similarly, game theory often assumes that each player is able to observe everyone else's actions, or at the very least know how many other players there are, but maintaining perfect system-wide information is impossible in most systems. In other words, not all incentive mechanisms are systems-compatible. The main contribution of this dissertation is the design, implementation, and evaluation of various systems-compatible incentive mechanisms and their application to a wide range of deployable systems. These systems include BitTorrent, which is used to distribute a large file to a large number of downloaders, PeerWise, which leverages user cooperation to achieve lower latencies in Internet routing, and Hoodnets, a new system I present that allows users to share their cellular data access to obtain greater bandwidth on their mobile devices. Each of these systems represents a different point in the design space of systems-compatible incentives. Taken together, along with their implementations and evaluations, these systems demonstrate that systems-compatibility is crucial in achieving practical incentives in real systems. I present design principles outlining how to achieve systems-compatible incentives, which may serve an even broader range of systems than considered herein. I conclude this dissertation with what I consider to be the most important open problems in aligning the competing interests of the Internet's participants

Motivating Participation in Internet Routing Overlays

PeerWise is an Internet routing overlay that reduces end-to-end latencies by allowing peers to forward through a relay instead of connecting directly to their destinations. Fundamental to PeerWise is the notion of peering agreements between two peers, wherein they agree to forward for one another. In this paper, we consider the problem of motivating users to establish and maintain peerings in a completely decentralized, scalable manner. We show that routing overlays present unique challenges and goals. For instance, since participants can always “fall back ” on standard Internet routing, we must encourage users to stay in the system and maintain long-lived peering agreements. To address these challenges, we propose two mechanisms: First, we use Service Level Agreements (SLAs) to expressively negotiate peers ’ demands and the recourses they will take when SLAs are violated. Second, we propose a mechanism to address SLA violations that differs from the standard notion of punishment via service degradation. Our simulation results demonstrate that our mechanism causes peers to avoid SLA violators in favor of long-lived peerings. Lastly, we discuss potential, emergent behaviors in a selfish routing overlay. Categories and Subject Descriptor