Yefeng Liu

Using stranger as sensors: temporal and geo-sensitive question answering via social media

MoboQ is a location-based real-time social question answering service deployed in the field in China. Using MoboQ, people can ask temporal and geo-sensitive questions, such as how long is the line at a popular business right now, and then receive answers that crowdsourced from other users in a timely fashion. To obtain answers for questions, the system analyzes the live stream from public microblogging service Sina Weibo to identify people who are likely to currently be at the place that is associated with a question and sends them the unsolicited question through the microblogging service from which they were identified. MoboQ was deployed in China at the beginning of 2012, until October of the same year, it was used to ask 15,224 questions by 35,214 registered users, and it gathered 29,491 answers; 74.6% of the questions received at least one answer, 28% received a first response within 10 minutes, and 51% of the questions got first answer within 20 minutes. In total, 91% of the questions successfully found at least one answer candidate, and they were sent to 162,954 microblogging service users. We analyze the usage patterns and behaviors of the real-world end-users, discuss the lessons learned, and outline the future directions and possible applications that could be built on top of MoboQ.

Drawing on mobile crowds via social media Case UbiAsk: Image based mobile social search across languages

Recent years have witnessed the impact of crowdsourcing model, social media, and pervasive computing. We believe that the more significant impact is latent in the convergence of these ideas on the mobile platform. In this paper, we introduce a mobile crowdsourcing platform that is built on top of social media. A mobile crowdsourcing application called UbiAsk is presented as one study case. UbiAsk is designed for assisting foreign visitors by involving the local crowd to answer their image-based questions at hand in a timely fashion. Existing social media platforms are used to rapidly allocate microtasks to a wide network of local residents. The resulting data are visualized using a mapping tool as well as augmented reality (AR) technology, result in a visual information pool for public use. We ran a controlled field experiment in Japan for 6 weeks with 55 participants. The results demonstrated a reliable performance on response speed and response quantity: half of the requests were answered within 10 min, 75% of requests were answered within 30 min, and on average every request had 4.2 answers. Especially in the afternoon, evening and night, nearly 88% requests were answered in average approximately 10 min, with more than 4 answers per request. In terms of participation motivation, we found the top active crowdworkers were more driven by intrinsic motivations rather than any of the extrinsic incentives (game-based incentives and social incentives) we designed.

A crowdsourcing based mobile image translation and knowledge sharing service

Travelers in countries that use an unfamiliar script cannot use pocket translators or online translation services to understand menus, maps, signs and other important information, because they are unable to write the text they see. Solutions based on optical character recognition provide very limited performance in real-world situations and for complex scripts such as Chinese and Japanese. In this paper, we propose an alternative image translation solution based on crowdsourcing. A large number of human workers on mobile terminals are used to carry out the tasks of image recognition, translation and quality assurance. Compared to purely technical solutions, this human computation approach is also able to account for context and non-textual cues, and provide higher level information to the end-user. In this paper, we describe a preliminary user study to create a model of end-user requirements.

Achieving sustainable society through micro-level crowdfunding

This paper proposes a new approach for motivating people to participate in achieving a sustainable society. The method is called Micro-Crowdfunding, and encourages people living in urban cities to support and contribute to the sustainability of small common resources, such as public sinks, toilets, shelves, office areas and so on. Micro-Crowdfunding is based on the crowdfunding concept and uses the local currency idea, as tools of the social mechanism, to increase peoples awareness of how they participate in keeping the sustainability of common resources. Our approach aims to maintain the sustainability of common resources with peoples small efforts. In this approach, an organizer introduces a new mission for keeping the sustainability of a resource, and investors fund it. Finally, a performer executes the mission, and completes it with minimal efforts achieving the resources sustainability.

Family interaction for responsible natural resource consumption

In this paper we propose a novel approach to persuasive technology, based on children-parent interaction, to be implemented in a smart pad ludic application; to contribute to the natural resource consumption problem, not only by raising awareness, but by encouraging informed decisions on their use. We conducted a survey to see which natural resources are more relevant to Japanese society. We designed an attractive multimedia tool, considering the family interaction, that uses eco-visualizations, a narrative and cartoon characters. If successful, we would achieve better informed consumption of food and other natural resources, reinforcing positive attitudes within the family.

Mobile Image Search via Local Crowd: A User Study

In this paper we present a on-field study for evaluating a crowd sourcing mobile social search application. With the help of the local crowd via social medias, this application assists foreign visitors in Japan by answering their image-based questions at hand in a timely fashion. We ran a controlled field experiment for 6 weeks with 55 participants. We found that the mobile crowd sourcing model demonstrated a reliable performance on response speed and response quantity: half of the requests were answered within 10 minutes, 75% of requests were answered within 30 minutes, and on average every request had 4.2 answers. Especially in the afternoon, evening and night, nearly 88% requests were answered in average approximately 10 minutes, with more than 4 answers per request. In terms of participation motivation, we found the top active crowd workers were more driven by intrinsic motivations rather than any of the extrinsic incentives (gamification incentives and social incentives) we designed.

Designing Incentives for Community-Based Mobile Crowdsourcing Service Architecture

Good design strategies for designing social media are important for their success, but current designs are usually ad-hoc, relying on human intuition. In this paper, we present an overview of three community-based mobile crowdsourcing services that we have developed as case studies. In community-based mobile crowdsourcing services, people voluntarily contribute to help other people anytime and anywhere using mobile phones. The task required is usually trivial, so people can perform it with a minimum effort and low cognitive load. This approach is different from traditional ones because service architecture designers need to consider the tradeoff among several types of incentives when designing a basic architecture. We then extract six insights from our experiences to show that motivating people is the most important factor in designing mobile crowdsourcing service architecture. The design strategies of community-based mobile crowdsourcing services explicitly consider the tradeoff among multiple incentives. This is significantly different from the design in traditional crowdsourcing services because their designers usually consider only a few incentives when designing respective social media. The insights are valuable lessons learned while designing and operating the case studies and are essential to successful design strategies for building future more complex crowdsourcing services.

Facilitating natural flow of information among "taste-based" groups

Social science studies have shown that the disconnection of people from different social classes or opinion groups may reinforce serious problems to our society (e.g., residential segregation, group polarization, or confirmation bias). With the emerging trend of the Web 2.0, however, different kinds of people are likely having less chance to share information with each other. How to design for supporting better information flow among different social, taste, or opinion groups of people becomes a challenging question for digital designers. In this work-in-progress paper we present our on-going research of exploring a crowd-based system for facilitating natural information flow among different types of people. We conducted a Wizard-of-OZ study to simulate push-based human powered recommendation, and learn how participants react when receiving unexpected information. Based on the findings, we designed and implemented a web application for encouraging different kinds of people to exchange information in a peer-to-peer way. Next steps include designing pairing strategy and conducting user study.

Design and Evaluation of Micro-Crowdfunding: Encouraging Sustainable Behavior in Micro-Level Crowdfunding

We present the basic concept of Micro-Crowdfunding and its prototype system. We also describe its experimental results that show how economic and social factor affect the behavior and attitude of an individual and community. We believe that our study given in this paper would be also useful when designing other social media based on crowdfunding when considering the balance using between the economic and social incentives.