Studying user behavior through a participatory sensing framework in an urban context

A thesis submitted in partial fulfillment of the requirements for the degree of Doctor in Information Management, specialization in Geographic Information SystemsThe widespread use of mobile devices has given birth to participatory sensing, a data collection approach leveraging the sheer number of device users, their mobility, intelligence and device’s increasingly powerful computing and sensing capabilities. As a result, participatory sensing is able to collect various types of information at a high spatial and temporal resolution and it has many applications ranging from measuring cellular signal strength or road condition monitoring to observing the distribution of birds. However, in order to achieve better results from participatory sensing, some issues needed to be dealt with. On a high level, this thesis addressed two issues: (1) the design and development of a participatory sensing framework that allows users to flexibly create campaigns and at the same time collect different types of data and (2) the study of different aspects of the user behaviors in the context of participatory sensing. In particular, the first contribution of the thesis is the design and development of Citizense, a participatory sensing framework that facilitates flexible deployments of participatory sensing campaigns while at the same time providing intuitive interfaces for users to create sensing campaigns and collect a variety of data types. During the real-world deployments of Citizense, it has shown its effectiveness in collecting different types of urban information and subsequently received appreciation from different stakeholders. The second contribution of the thesis is the in-depth study of user behavior under the presence of different monetary incentive mechanisms and the analysis of the spatial and temporal user behavior when participants are simultaneously exposed to a large number of participatory sensing campaigns. Concerning the monetary incentive, it is observed that participants prefer fixed micro-payment to other mechanisms (i.e., lottery, variable micro-payment); their participation was increased significantly when they were given this incentive. When taking part in the participatory sensing process, participants exhibit certain spatial and temporal behaviors. They tend to primarily contribute in their free time during the working week, although the decision to respond and complete a particular participatory sensing campaign seems to be correlated to the campaign’s geographical context and/or the recency of the participants’ activities. Participants can be divided into two groups according to their behaviors: a smaller group of active participants who frequently perform participatory sensing activities and a larger group of regular participants who exhibit more intermittent behaviors

Do Monetary Incentives Influence Users’ Behavior in Participatory Sensing?

Participatory sensing combines the powerful sensing capabilities of current mobile devices with the mobility and intelligence of human beings, and as such has to potential to collect various types of information at a high spatial and temporal resolution. Success, however, entirely relies on the willingness and motivation of the users to carry out sensing tasks, and thus it is essential to incentivize the users’ active participation. In this article, we first present an open, generic participatory sensing framework (Citizense) which aims to make participatory sensing more accessible, flexible and transparent. Within the context of this framework we adopt three monetary incentive mechanisms which prioritize the fairness for the users while maintaining their simplicity and portability: fixed micro-payment, variable micro-payment and lottery. This incentive-enabled framework is then deployed on a large scale, real-world case study, where 230 participants were exposed to 44 different sensing campaigns. By randomly distributing incentive mechanisms among participants and a subset of campaigns, we study the behaviors of the overall population as well as the behaviors of different subgroups divided by demographic information with respect to the various incentive mechanisms. As a result of our study, we can conclude that (1) in general, monetary incentives work to improve participation rate; (2) for the overall population, a general descending order in terms of effectiveness of the incentive mechanisms can be established: fixed micro-payment first, then lottery-style payout and finally variable micro-payment. These two conclusions hold for all the demographic subgroups, even though different different internal distances between the incentive mechanisms are observed for different subgroups. Finally, a negative correlation between age and participation rate was found: older participants contribute less compared to their younger peers

Untersuchung des Einsatzes monetärer Anreize in der Citizen Science

Die Teilnahme an Citizen Science kann Kosten verursachen, die die Motivationen der Teilnehmenden verringern kann. Wir glauben, dass der Einsatz von finanziellen Anreizen dieses Problem lindern und die Teilnahmebereitschaft fördern kann. Im Rahmen von fünf Citizen Science-Projekten untersucht diese Studie die monetäre Erwartungshaltung der deutschen Öffentlichkeit und deren Abhängigkeit von weiteren wichtigen Merkmalen (z.B. Spaß, Komplexität und Bedeutung). Die Ergebnisse zeigen, dass die Teilnahme an Citizen Science-Projekten durch eine geringe finanzielle Belohnung positiv beeinflusst wird. Im Allgemeinen steigt die Höhe der erwarteten Vergütung bei Projekten, die als zeitaufwändig oder kompliziert gelten und sinkt bei Projekten, die als wichtig erachtet werden. Diese Bewertung von wichtigen Merkmalen durch Teilnehmende und die daraus resultierenden empirischen Ergebnisse, können von der Projektleitung genutzt werden um eine angemessene Vergütung anzubieten

How the general public appraises contributory citizen science: Factors that affect participation

Understanding the factors that affect participation plays a crucial role in the success of any contributory citizen science project. We focus our study on the general public, who most likely have not participated in citizen science before, since they constitute a large part of society and their opinions have not been studied thoroughly. We first describe the survey, which was answered by 209 respondents in Germany who mostly had no prior experience in citizen science, that seeks to addressthe factors of personality traits, properties of citizen science projects, and general motivations. Our study focuses on two different levels of participation: in specific sample projects and in contributory citizen science in general, both of which are embedded in the survey. We use manual text clustering and linear regression models to study the different types of inputs from the respondents. We identify contribution to science, the fun element of the projects, personal interests, and new knowledge acquired from participation as the most significant motivators for the future intention of participating in the sample citizen science projects. On a higher level, the general motivations concerning “values” and “understanding” are the main drivers behind participants’ future intention of participating in contributory citizen science. Meanwhile, no personality traits are found to be influence the intentions of the respondents. Based on these findings, several enhancements to the recruitment and communication strategies of citizen science projects can be made to maximize the participation of potential citizen scientists

Understanding how personalities and motivations affect participation in Citizen science

As citizen science projects heavily rely on their members’ voluntary participation in contributing ideas, co-creating projects and especially collecting data, it is crucial to understand motivations and factors that affect an individual’s decision to take part. This study seeks to understand how people’s personality traits affect their appraisal of citizen science projects and their likelihood of participating in them. We selected five typical citizen science projects that represent a broad range of topics, levels of difficulty and execution modes as a basis for our investigation. While other studies only focus on the motivation of participants who already took part in citizen science activities, this study also targets participants without prior experience, who might volunteer in citizen science projects in the future. By using a structured survey that includes questions on personality traits, functional motives and subjective evaluation of the five sample projects, we seek to report respondents’ most important intrinsic motivations for citizen science. Apart from these intrinsic motivations, we also explore the use of monetary incentives to encourage participation in citizen science tasks, which might be used in the future to recruit participants and improve data quality. The study participants’ expectations regarding monetary rewards can be used to improve existing algorithms and design new methods that fairly and efficiently distribute rewards

The Feuerkugel app: A co-designed mobile application for documenting fireballs

Fireballs, also known as bolides, not only generate excitement among the general public with its spectacular display of light in the atmosphere, but they also hold valuable information about our solar system. Therefore, the record of their occurrences and the reconstruction of their trajectories are much desired, especially when the latter leads to the collection of fireball remnants reaching the Earth’s surface, which packs vast amount of unique information on the universe. However, many fireball events go unrecorded due to the limited coverage and frame rate of existing sky surveillance camera networks. To bridge this gap, a collaborative effort involving astronomy enthusiasts, astrophysicists, and data scientists has given rise to the Nachlicht-BüHNE project, in which a web-app called “Feuerkugel” enables all interested persons to intuitively submit detailed descriptions of fireball events. Each description includes the duration and color of the event, and the direction of the fireball’s trajectory, which can be effortlessly observed by our eyes. These parameters are subsequently used to reconstruct the trajectory of a fireball. As the web-app received increasing attention from the general public and collected a large number of fireball reports, we are examining the quality and quantity of the submitted fireball reports of the last 3 years. Fireball events recorded by the web-app are compared with records of dedicated sky surveillance camera networks in Germany and France. Based on this analysis, further improvements of the current tool that helps human observers to report fireball events and the data processing methods can be implemented. Additionally, we are analyzing the error of the reconstructed flight trajectories. Therefore, the web-app is extended to allow users the selection and mapping of high-flying commercial aircrafts, with known flight tracks, instead of fireballs. The retrieved trajectories of aircrafts are compared with their known flight tracks to estimate the positional error that we transfer to fireball trajectories afterwards. In this contribution, we present the added value arising from the participation of different stakeholder groups, the structure of the web-app resulting from this participative approach and selected results of the quality and quantity analysis

Studying the participants’ response to reverse-auction mechanisms that allocate monetary incentive in citizen science

The recruitment of participants in a citizen science project should address various possible costs and obstacles to participants that might emerge during the execution of the project. In this context, monetary incentives have the potential to alleviate this problem by compensating for part of these efforts and thus sustain the citizen scientists’ participation. Nevertheless, they have not been studied thoroughly in citizen science literature and have rarely been deployed. Reverse-auction mechanisms are promising methods to distribute a project’s fixed budget among the participants as winners are selected based on participants’ bid prices. However, the outcome entirely depends on these bid prices, which are not available to the project organizers in advance and can vary largely. Therefore, it is desirable to assert certain control over the participants’ bid prices. We propose the approach of “desired bid price”, in which a pre-calculated bid price suitable to a project is shown to the bidders before determining their bid prices. While participants are eventually free to select their bid price, they are informed that a bid price lower than the shown value might increase their chance of winning the bid. As a result, it is expected that overall bid prices might better fit to a predefined project budget. This approach can be implemented in various contributory citizen science projects together with the control approach, in which participants determine their bid price without additional information. The differences in bidding behaviors and outcomes of the two approaches will be analyzed. Finally, the results can be used to further refine the existing reverse-auction mechanisms and eventually pave the way for the broader use of monetary incentives in citizen science

How monetary incentives potentially improve the recruitment of participants in citizen science: Results from a survey in Germany

The success of citizen science projects often relies on the participation of a large number of participants to collect sufficient amount of data that can be processed later by scientists. While it is known that participation in citizen science is voluntary and typically is based on the participants’ intrinsic motivations, other aspects such as obstacles and extrinsic motivations, with monetary incentive as an example, have not been studied adequately yet. Furthermore, it is estimated that only a fraction of the population has actively involved in citizen science. Therefore, based on some initial success stories of deploying monetary incentive in citizen science, we believe that this type of incentive could be used to improve the recruitment of potential participants in citizen science projects and sustain the participation of citizen scientists. In the literature, several incentive algorithms have been proposed to fairly and efficiently distribute a project budget to the participants. However, the real monetary expectation of the general public has not been considered thoroughly in the design and simulation of these algorithms. Consequently, we conduct a survey on the intrinsic motivations and monetary expectations for citizen science among the public in Germany. Through five sample projects that cover various domains of science, 230 adults who mostly have not taken part in citizen science earlier have expressed their intrinsic motivations and desired monetary rewards for their future participation in these projects. On one hand it was found that their future participation is motivated by contribution to science, fun element of the projects, their personal interests and new knowledge. On the other hand, a majority of the respondents would like to receive certain amount of rewards. The results of this study can be beneficial to various stakeholders. First, algorithm designers can use the respondents’ desired amount of rewards to improve their incentive mechanisms. Second, project organizers can effectively communicate their citizen science projects to the public by stressing the project attributes relevant to the public’s motivations. Finally, by combining existing theoretical algorithms and the empirical expectations from the general public, the feasibility of deploying monetary incentive in citizen science can be shown

Sensor Communication in Smart Cities and Regions: An Efficient IoT-Based Remote Health Monitoring System

Recent advances in Information and Communication Technology (ICT), especially those related to the Internet of Things (IoT), are facilitating smart regions. Among many services that a smart region can offer, remote health monitoring is a typical application of IoT paradigm. It offers the ability to continuously monitor and collect health-related data from a person, and transmit the data to a remote entity (for example, a healthcare service provider) for further processing and knowledge extraction. An IoT-based remote health monitoring system can be beneficial in rural areas belonging to the smart region wherepeople have limited access to regular healthcare services. The same system can be beneficial in urban areas where hospitals can be overcrowded and where it may take substantial time to avail healthcare. However, this system may generate a large amount of data. In order to realize an efficient IoT-based remote health monitoring system, it is imperative to study the network communication needs of such a system; in particular the bandwidth requirements and the volume of generated data. The thesis studies a commercial product for remote health monitoring in Skellefteå, Sweden. Based on the results obtained via the commercial product, the thesis identified the key network-related requirements of a typical remote health monitoring system in terms of real-time event update, bandwidth requirements and data generation. Furthermore, the thesis has proposed an architecture called IReHMo - an IoT-based remote health monitoring architecture. This architecture allows users to incorporate several types of IoT devices to extend the sensing capabilities of the system. Using IReHMo, several IoT communication protocols such as HTTP, MQTT and CoAP has been evaluated and compared against each other. Results showed that CoAP is the most efficient protocol to transmit small size healthcare data to the remote servers. The combination of IReHMo and CoAP significantly reduced the required bandwidth as well as the volume of generated data (up to 56 percent) compared to the commercial product. Finally, the thesis conducted a scalability analysis, to determine the feasibility of deploying the combination of IReHMo and CoAP in large numbers in regions in north Sweden.Validerat; 20150812 (global_studentproject_submitter

Analyzing Spatial and Temporal User Behavior in Participatory Sensing

The large number of mobile devices and their increasingly powerful computing and sensing capabilities have enabled the participatory sensing concept. Participatory sensing applications are now able to effectively collect a variety of information types with high accuracy. Success, nevertheless, depends largely on the active participation of the users. In this article, we seek to understand spatial and temporal user behaviors in participatory sensing. To do so, we conduct a large-scale deployment of Citizense, a multi-purpose participatory sensing framework, in which 359 participants of demographically different backgrounds were simultaneously exposed to 44 participatory sensing campaigns of various types and contents. This deployment has successfully gathered various types of urban information and at the same time portrayed the participants’ different spatial, temporal and behavioral patterns. From this deployment, we can conclude that (i) the Citizense framework can effectively help participants to design data collecting processes and collect the required data, (ii) data collectors primarily contribute in their free time during the working week; much fewer submissions are done during the weekend, (iii) the decision to respond and complete a particular participatory sensing campaign seems to be correlated to the campaign’s geographical context and/or the recency of the data collectors’ activities, and (iv) data collectors can be divided into two groups according to their behaviors: a smaller group of active data collectors who frequently perform participatory sensing activities and a larger group of regular data collectors who exhibit more intermittent behaviors. These identified user behaviors open avenues to improve the design and operation of future participatory sensing applications