Marshini Chetty

Measuring broadband performance in South Africa

Broadband penetration is increasing in South Africa, particularly on mobile devices, but little is known about the performance of fixed or mobile broadband in the country. This lack of empirical data imposes significant limitations to innovation, because broadband performance metrics help users audit their connectivity costs and regulators to make informed decisions about policies and infrastructure investments. We present the results from a measurement study of both fixed and mobile broadband connections in South Africa. We use measurement software that we implemented on mobile phones and home routers and adapted to address challenges that are unique to the developing world. Our findings suggest that consumers in South Africa are not getting advertised speeds, that mobile broadband generally has higher throughput than fixed broadband, and that interconnection between ISPs (or lack thereof) plays a significant role in determining the reliability and performance that users ultimately receive. Often, high latencies to destinations introduce significant performance bottlenecks, suggesting that, in addition to investments in higher throughput links, effort should be devoted to improving interconnection between ISPs and locating content closer to users. Our study, along with our open source technical platform, embodies an archetypal method for monitoring broadband performance in developing countries.

Peering at the Internet's Frontier: A First Look at ISP Interconnectivity in Africa

In developing regions, the performance to commonly visited destinations is dominated by the network latency, which in turn depends on the connectivity from ISPs in these regions to the locations that host popular sites and content. We take a first look at ISP interconnectivity between various regions in Africa and discover many circuitous Internet paths that should remain local often detour through Europe. We investigate the causes of circuitous Internet paths and evaluate the benefits of increased peering and better cache proxy placement for reducing latency to popular Internet sites.

A mixed-methods study of mobile users' data usage practices in South Africa

With a shift towards usage-based billing, the questions of how data costs affect mobile Internet use and how users manage mobile data arise. In this paper, we describe a mixed-methods study of mobile phone users data usage practices in South Africa, a country where usage-based billing is prevalent and where data costs are high, to answer these questions. We do so using a large scale survey, in-depth interviews, and logs of actual data usage over time. Our findings suggest that unlike in more developed settings, when data is limited or expensive, mobile Internet users are extremely cost-conscious, and employ various strategies to optimize mobile data usage such as actively disconnecting from the mobile Internet to save data. Based on these findings, we suggest how the Ubicomp and related research communities can better support users that need to carefully manage their data to optimize costs.

Hci for community and international development

This workshop explores the challenges in applying, extending and inventing appropriate methods and contributions of Human Computer Interaction (HCI) to International economic and community Development. We address interaction design for parts of the world that are often marginalized by the Global North as well as people in the Global North who are themselves similarly marginalized by poverty or other barriers. We hope to extend the boundaries of the field of Human Computer Interaction by spurring a discussion on how existing methods and practices can be adapted and modified, and how new practices can be developed, to deal with the unique challenges posed by these contexts.

uCap: An Internet Data Management Tool For The Home

Internet Service Providers (ISPs) have introduced data caps, or quotas on the amount of data that a customer can download during a billing cycle. Under this model, Internet users who reach a data cap can be subject to degraded performance, extra fees, or even temporary interruption of Internet service. For this reason, users need better visibility into and control over their Internet usage to help them understand what uses up data and control how these quotas are reached. In this paper, we present the design and implementation of a tool, called uCap, to help home users manage Internet data. We conducted a field trial of uCap in 21 home networks in three countries and performed an in-depth qualitative study of ten of these homes. We present the results of the evaluation and implications for the design of future Internet data management tools.

I want to imagine how that place looks: designing technologies to support connectivity between africans living abroad and home

Uneven access to Information and Communication Technologies (ICTs) in parts of the African continent make it challenging for some Africans who migrate to the U.S. to communicate with family members in their countries of origin. However, Internet access is becoming more widespread throughout the continent and this development presents an opportunity to explore how future interactive systems can support exchanges between families with members living in developed and less developed countries. To investigate these design possibilities we interviewed 27 African-born students, currently living in Virginia, U.S., and asked them how they used ICTs to connect with family members in their home countries. Our findings informed the development of a low-fidelity prototype that eight students lived with for four to five months. Findings from this deployment study motivate a discussion regarding features to include in interfaces designed to support transnational family communication. Features include personally meaningful imagery, country specific content, and the ability to monitor the weather and changing currency rates in migrants countries of origin.

Spiders in the Sky: User Perceptions of Drones, Privacy, and Security

Drones are increasingly being used for various purposes from recording footage in inaccessible areas to delivering packages. A rise in drone usage introduces privacy and security concerns about flying boundaries, what data drones collect in public and private spaces, and how that data is stored and disseminated. However, commercial and personal drone regulations focusing on privacy and security have been fairly minimal in the USA. To inform privacy and security guidelines for drone design and regulation, we need to understand users perceptions about drones, privacy and security. In this paper, we describe a laboratory study with 20 participants who interacted with a real or model drone to elicit user perceptions of privacy and security issues around drones. We present our results, discuss the implications of our work and make recommendations to improve drone design and regulations that enhance individual privacy and security.

'No Telling Passcodes Out Because They're Private': Understanding Children's Mental Models of Privacy and Security Online

Children under age 12 increasingly use Internet-connected devices to go online. And while Internet use exposes people to privacy and security risks, few studies examine how these children perceive and address such concerns. To fill this gap, we conducted a qualitative study of 18 U.S. families with children ages 5-11. We found that children recognized certain privacy and security components from the contextual integrity framework, but children ages 5-7 had gaps in their knowledge. Children developed some strategies to manage concerns but largely relied on parents for support. Parents primarily used passive strategies to mediate childrens device use and largely deferred teaching children about these concerns to the future. We argue that helping children develop strong privacy and security practices at a young age will prepare them to manage their privacy and security as adolescents and adults. We offer recommendations to scaffold childrens learning on privacy and security.

Co-designing online privacy-related games and stories with children

Children ages 8--12 spend nearly six hours per day with digital content, but they receive little formal instruction related to managing privacy online. In this study, we explore how games and storytelling can inform the development of resources to help children learn about privacy online. We present results from three co-design sessions with a university-based intergenerational design team that included eight children ages 8--11. During these sessions, we reviewed existing privacy resources with children and elicited design ideas for new resources. Our findings yield several recommendations for designers. Specifically, online privacy-focused educational resources should: (1) include relatable elements such as familiar characters and easily understandable storylines, (2) go beyond instructing children through dos and donts and equip children to make privacy-related decisions, and (3) expose children to a range of privacy consequences, highlighting the positive and negative outcomes that can result from disclosing and managing information online.

Understanding the Use and Impact of the Zero-Rated Free Basics Platform in South Africa

Companies are offering zero-rated, or data-charge free Internet services to help bring unconnected users online where Internet access is less affordable. However, it is unclear whether these services achieve this goal or how they shape Internet use. To inform evidence-based policy around and the design of zero-rated services, we show in this paper how mobile users are making use of Facebooks controversial Free Basics platform. We present findings from interviews of 35 Free Basics users in South Africa: current low-income users and non-regular student users. Our findings suggest that Free Basics does shape Internet usage, for instance, users spend more time online because of free apps. Second, Free Basics saves users money but adoption of the platform depends on access to other free Internet options. Finally, most users are confused about how zero-rated services work and what free means. Based on our findings, we make recommendations for future work.