Digital tabletop computers are an ideal platform for games with the social advantages of traditional tabletop games, such as board games and card games, combined with the more streamlined and automated gameplay of video games. Implementing a board game digitally allows for aspects of the game, such as routine in-game activities, rule enforcement and game progression, to be automated. However, the effect of this automation on the players’ social experience and enjoyment is poorly understood. To explore this question, a mixed-method study was carried out in which 24 groups of participants played either the abstract strategy board game Checkers or the cooperative board game Pandemic using three different interfaces: the original physical game; a digital tabletop interface which provided minimal automation in an attempt to replicate play of the original game; and a digital tabletop interface which automated many in-game activities, enforced the rules and managed the progression of the game. The study revealed that while automation does have the potential to reduce the overhead to play the game, it can lead to player frustration in several ways. Automating routine in-game activities and game progression can lead to severe awareness deficits. Automation of rule enforcement and management of the game state can streamline gameplay, but can lead to scenarios where players would prefer more control over the game. The negative space around the active game area is important to consider for storage of digital artifacts and physical objects above the table. Finally the digitization and automation of the games did not reduce social interaction, making digital tabletops a promising platform for social games. / Thesis (Master, Computing) -- Queen's University, 2012-01-08 10:32:08.405

This research details the development of a large-scale, computer vision-based touch screen capable of supporting a large number of simultaneous hand interactions. The system features a novel lightweight multi-point tracking algorithm to improve real-time responsiveness. This system was trialled for six months in an exhibition installation at World Expo 2005 in Aichi, Japan, providing a robust, fault-tolerant interface. A pilot study was then conducted to directly compare the system against other, more established input methods (a single-touch case, a two-mouse case and a physical prototype) to determine the effectiveness and affordances of the multi-touch technology for arranging information on a large-scale wall space in a paired collaborative task. To assist in this study, a separate visualisation and interaction classification tool was developed, allowing the replay of XML log data in real time to assist in the video analysis required for observation and hypothesis testing.

Multi-display environments (such as the pairing of a digital tabletop computer with a set of handheld tablet computers) can support collocated interaction in groups by providing individuals with private workspaces that can be used alongside shared interaction surfaces. However, such a configuration necessitates the inclusion of intuitive and seamless interactions to move digital objects between displays. While existing research has suggested numerous methods to bridge devices in this manner, these methods often require highly specialized equipment and are seldom examined using real-world tasks. This thesis investigates the use of two cross-device object transfer methods as adapted for use with commonly-available hardware and applied for use in a realistic task, a familiar tabletop card game. A digital tabletop and tablet implementation of the tabletop card game Dominion is developed to support each of the two cross-device object transfer methods (as well as two different turn-taking methods to support user identification). An observational user study is then performed to examine the effect of the transfer methods on groups’ behaviour, examining player preferences and the strategies which players applied to pursue their varied goals within the game. The study reveals that players’ choices and use of the methods is shaped greatly by the way in which each player personally defines the Dominion task, not simply by the objectives outlined in its rulebook. Design considerations for the design of cross-device object transfer methods and lessons-learned for system and experimental design as applied to the gaming domain are also offered.

Context. Smartphones contain advanced sensors called microelectromechanical systems(MEMS). By connecting a smartphone to a computer these sensors can be used to test new interaction techniques for games. Objective. This study aims to investigate an interaction technique implemented with a gyroscope that utilises the leaning of a user’s torso and compare it in terms of precision and enjoyment to using a joystick. Method. The custom interaction technique was implemented by using the gyroscope of a Samsung Galaxy s6 Edge and attaching it to to the torso of the user. The joystick technique was implementation by using the left joystick of an Xbox One controller. A user study was conducted and 19 people participated by playing a custom-made obstacle course game that tested the precision of the interaction techniques. After testing each technique participants took part in a survey consisting of questions regarding their enjoyment using the technique. Result. The results showed that the leaning technique was not as precise as the joystick implementation. The participants found the learning technique to be more fun to use and also more immersive compared to the joystick implementation. The leaning technique was however also more uncomfortable and difficult to use, and players felt less competent in their ability to control the player character with it. Conclusion. The performance difference might have been due to the lack of familiarity with the leaning technique compared to the joystick implementation. The leaning technique was more difficult to use and more uncomfortable than the joystick method. However, the leaning technique was also more fun to use and more immersive. This offers up the opportunity to keep exploring possibilities with this technique.

Bitcoin is a digital currency that is used by people all around the world. The goal of this paper is to give an idea about how much trust there is in bitcoin among its users. This paper has used an online survey aimed at bitcoinusers and a content analysis to collect data about this trust. The conclusions show that there seems to be some trust in bitcoin as a technology and this is based on that the users have a good understanding about how bitcoin works. They also share their knowledge about bitcoin to people around them. The trust between people in the bitcoin network on the contrary doesn’t seem as high because certain technological properties hurt this trust. The survey showed that only a small percentage of the users started to use bitcoin to buy and sell products, which may indicate a lower degree of trust in other people.

Due to limited hardware, effectively using the available resources is crucial for mobile games. Texture compression is a fundamental technique in game development to reduce the demand of memory and bandwidth usage. This thesis evaluates JPEG, PVRTC and uncompressed PVR with emphasis on loading time, memory footprint, application size and visual quality. The goal of this case study is to find the most suitable compression technique for a specific game. A variant of uncompressed PVR, RGBA4444, was found to be the best technique to use in this case. It was also concluded that JPEG compression in general is a bad choice for games due to the lack of an alpha channel. Severe visual artifacts were noticed on frame-by-frame animation when using PVRTC. It is therefore interesting to investigate other animation techniques, such as skeletal animation, in combination with texture compression, to avoid such artifacts.

User studies play a vital role in data visualization research because they help measure the strengths and weaknesses of different visualization techniques quantitatively. In addition, they provide insight into what makes one technique more effective than another; and they are used to validate research contributions in the field of information visualization. For example, a new algorithm, visual encoding, or interaction technique is not considered a contribution unless it has been validated to be better than the state of the art and its competing alternatives or has been validated to be useful to intended users. However, conducting user studies is challenging, time consuming, and expensive. User studies generally requires careful experimental designs, iterative refinement, recruitment of study participants, careful management of participants during the run of the studies, accurately collecting user responses, and expertise in statistical analysis of study results. There are several variables that are taken into consideration which can impact user study outcome if not carefully managed. Hence the process of conducting user studies successfully can take several weeks to months. In this dissertation, we investigated how to design an online framework that can reduce the overhead involved in conducting controlled user studies involving web-based visualizations. Our main goal in this research was to lower the overhead of evaluating data visualizations quantitatively through user studies. To this end, we leveraged current research opportunities to provide a framework design that reduces the overhead involved in designing and running controlled user studies of data visualizations. Specifically, we explored the design and implementation of an open-source framework and an online service (VisUnit) that allows visualization designers to easily configure user studies for their web-based data visualizations, deploy user studies online, collect user responses, and analyze incoming results automatically. This allows evaluations to be done more easily, cheaply, and frequently to rapidly test hypotheses about visualization designs. We evaluated the effectiveness of our framework (VisUnit) by showing that it can be used to replicate 84% of 101 controlled user studies published in IEEE Information Visualization conferences between 1995 and 2015. We evaluated the efficiency of VisUnit by showing that graduate students can use it to design sample user studies in less than an hour. Our contributions are two-fold: first, we contribute a flexible design and implementation that facilitates the creation of a wide range of user studies with limited effort; second, we provide an evaluation of our design that shows that it can be used to replicate a wide range of user studies, can be used to reduce the time evaluators spend on user studies, and can be used to support new research.

Many scholarly tasks involve working with contextualized fine-grain information, such as a music professor creating a multimedia lecture on a musical style, while bringing together several snippets of compositions of that style. We refer to such contextualized parts of a larger unit of information (or whole documents), as subdocuments. Current approaches to work with subdocuments involve a mix of paper-based and digital techniques. With the increase in the volume and in the heterogeneity of information sources, the management, organization, access, retrieval, as well as reuse of subdocuments becomes challenging, leading to inefficient and ineffective task execution. A digital library (DL) facilitates management, access, retrieval, and use of collections of data and metadata through services. However, most DLs do not provide infrastructure or services to support working with subdocuments. Superimposed information (SI) refers to new information that is created to reference subdocuments in existing information resources. We combine this idea of SI with traditional DL services, to define and develop a DL with SI (an SI-DL). Our research questions are centered around one main question: how can we extend the notion of a DL to include SI, in order to support scholarly tasks that involve working with subdocuments? We pursued this question from a theoretical as well as a practical/user perspective. From a theoretical perspective, we developed a formal metamodel that precisely defines the components of an SI-DL, building upon related work in DLs, SI, annotations, and hypertext. From the practical/user perspective, we developed prototype superimposed applications and conducted user studies to explore the use of SI in scholarly tasks. We developed SuperIDR, a prototype SI-DL, which enables users to mark up subimages, annotate them, and retrieve information in multiple ways, including browsing, and text- and content-based image retrieval. We explored the use of subimages and evaluated the use of SuperIDR in fish species identification, a scholarly task that involves working with subimages. Findings from the user studies and other work in our research lead to theory- and experiment-based enhancements that can guide design of digital libraries with superimposed information. / Ph. D.

Group signature schemes enable anonymous-yet-accountable communications. Such a capability is extremely useful for modern applications such as smartphone-based crowdsensing and citizen science. A prototype named GROUPSENSE was developed to support anonymous-yet-accountable crowdsensing with SRBE in Android devices. From this prototype, an Android crowdsensing application was implemented to support privacy in citizen science. In this thesis, we will evaluate the usability of our privacy-preserving crowdsensing application for citizen science projects. An in person user study with 22 participants has been performed showing that participants understood the importance of privacy in citizen science and were willing to install privacy-enhancing applications, yet over half of the participants did not understand the privacy guarantee. Based on these results, modifications to the crowdsensing application have been made with the goal of improving the participants' understanding of the privacy guarantee. / Master of Science

When watching interactive branched video, the viewer is given the opportunity to tailor the storyline of the video playback. This type of video puts the users in control of their viewing experiences and provides content creators with great flexibility how to personalize the viewing experience for individual viewers. When it comes to regular linear videos, the concept of having a playback bar visually presenting the playback is a well established implementation used for most (if not all) video players, but for interactive branched videos, that is not the case. Instead, most branched video implementations are typically custom-made on a per-video basis (e.g., see custom-made Netflix and BBC movies) and do not use a playback bar. With the goal to fill this void, a branched video player with a generalized playback bar that visualizes the tree-like video structure was developed in 2018 by students of the Information Technology program at Linköping University and will be made public with a publication in the near future. Within the preparatory work prior to making this branched video player public, this project included a three-phase user study, where we evaluated the playback bar and its implemented features and compared the video player with alternative designs. With this thesis, we highlight the value of a branched video playback bar and provide interesting insights into how it, and other design customization features, may best be integrated into a branched video player. Furthermore, we present an improved version of the video player in which the new implementations are based on, and motivated by, the results from the user study. Finally, we describe how further investigations may be done to evaluate the improved version of the video player.