Purpose: The objective of this study is to illustrate how participants in leaderless based projects communicate with each other. Several studies have focused on technology-supported projects, such as open source projects, with an established project manager and goal. There is a lack, to the best of our knowledge, in studies that deal with the communication pattern in a leaderless computer supported collaborative project. Method: We have chosen to use a quantitative method where we systematically group several messages according to their content. This method was used in a similar study to illustrate the communication between participants involved in an open source project. We have taken the same Kripendorff based method and adapted it to our study by adding more descriptive variables. Theoretical perspectives: Manuel Castell discusses the aspects of a new communication power that is rooted in the individual as part of a larger creative audience. The collaborative works we have studies are prime examples of how the creative audience works together and of mass self‐communication. In order to analyze the potential motivations behind the participant’s involvement in these collaborative works, we have adopted the ideas of Preece and Shneidermans frame theory. They have identified 4 major roles in most onlinebased co‐operations and refer to them as reader, contributor, collaborator and leader. Result: Our results show that the communication in computer supported collaborative works is characterized by positive and energetic communication. The participants are all involved by their own will; they contribute because they want to. We believe this to be the major factor influencing the flow and form of communication between the participants. The majority of posts are comments to other participants or contributing posts that add to the progression of the discourse. We also have reason to believe that the use of smileys and embedded pictures is related to the tools available to the participants; the quicker and easier it is to add a picture the more likely the participants will use these tools.

Despite the proliferation of large-scale displays in the workplace, creating groupware applications that take advantage of their potential for collaboration and communication remains a challenge. Interactions with large displays yield user experiences that are quite different from interaction with conventional desktop groupware. Thus, unique hurdles exist for designing and deploying large display groupware applications (LDGAs) that are useful and adopted into actual work practice In this dissertation we uncover and address some of the primary challenges for large display groupware applications though the design, development, deployment and evaluation of LDGA systems, as well as through the analysis of existing deployed LDGA systems. We present novel LDGA designs that address the issues of information awareness and informal communication through the use of large shared displays in workplaces and describe the findings from evaluations of their deployments. We then discuss a broad study of several existing LDGAs that we conducted and a framework of adoption challenges that we subsequently derived. We describe the application of this framework to the design a large display groupware application for supporting lightweight communication among workgroup members. We also present a field study of the use of LDGAs within the context of multi-display environments, looking specifically at the display technologies used by NASA scientists and engineers for the Mars Exploration Rover (MER) missions. This work uncovers how the display environment provides flexible support for science tasks as collaboration styles and mission goals evolve. We offer suggestions for how LDGAs should be designed and evaluated in light of our findings regarding the roles of LDGAs within an ecology of displays. Finally, we use the results of this evaluation as input for further refining our framework for LDGA adoption challenges.

Current shared file systems (NFS and SAMBA) are based on the local area network model. To these file systems, performance is the major issue. However, as the Internet grows, so does the distance between users and the Local Area Network. With this increase in distance, the latency increases as well. This creates a problem when multiple users attempt to work in a shared environment. Traditionally, the only way to collaborate over the Internet required the use of locks. These requirements motivated the creation of the State Difference Transformation algorithm that allows users non-blocking and unconstrained interaction across the Internet on a tree based structure. Fine Grain Locking, on the other hand, allows a user the ability to set a lock on a character or range of characters while using a form of the transformation algorithm listed above. This thesis proposes an implementation that integrates these two technologies as well as demonstrating the effectiveness and flexibility of State Difference Transformation. The implementation includes two applications that can be used to further research in both the transformation and locking communities. The first application allows users to create tests for SDT and Fine Grain Locking and verify the correctness of the algorithms in any given situation. The second application then furthers this research by creating a real-world groupware interface to a shared file system based on a clientserver architecture. This implementation demonstrates the usability and robustness of these algorithms in real world situations.

Many sources of rules govern our interactions with technology and our behavior online—law, ethical guidelines, community norms, website policies—and they do not always agree. This is particularly true in the context of content production because copyright law represents a collection of complex policies that often do not always account for the ways that people use and re-use digital media. Within legal gray areas, people make decisions every day about what is allowed, often negotiating multiple sources of rules. How do content creators make decisions about what they can and cannot do when faced with unclear rules, and how does the law (and perceptions of the law) impact technology use, creativity, and online interaction? Combining in-depth interviews, large-scale content analysis, and surveys, my work examines the complex relationship between law, site policy, norms, and technology. This dissertation provides a better understanding of how content creators engage with copyright and how norms organically form within communities of creators. It concludes with a set of design and policy recommendations for online community designers to help better support current practices among content creators.

This research examines mixed reality meetings, a context where individuals attend to both face-to-face group members while multitasking with technology. In these meetings, members engage simultaneously with those physically present and those outside of the meeting (virtual communication partners). Technology multitasking in meetings has a dual effect: it not only impacts the individual user, it has the potential to transform how collocated groups communicate and work together since attention becomes fragmented across multiple competing tasks. Qualitative and quantitative methods were used to investigate mixed reality meetings across four themes: (1) the factors contributing to the likelihood to multitask based on meeting type, polychronicity (one’s preference for multitasking), and cohesion beliefs, (2) behavior during mixed reality assessed by copresence management, (3) attitudes toward technology multitasking, and (4) subjective outcomes measured by perceived productivity and meeting satisfaction. The qualitative data set consists of fieldwork from a global software company and interviews with 8 information workers. The quantitative data are comprised of survey results from the fieldwork site (n=156) and an online panel of information workers (n=110). Results indicate that information workers perceive distinct meeting types that are associated with implicit norms for appropriate technology multitasking. These norms varied based on the relevance of a meeting segment and if a power figure was present. A higher preference score for multitasking (high polychronicity) was significantly correlated with increased technology multitasking and perceived productivity. Members of cohesive teams exhibited the most technology multitasking and perceived their teammates multitasking as appropriate. However, outsiders who exhibited the same behaviors were viewed as rude and distracting. Overall, information workers who multitasked during meetings did so with electronic communication tasks (e-mail and instant messaging) as opposed to other computing tasks (e.g. writing documents, researching information). These findings are discussed in relation to psychological studies on multitasking, computer-supported cooperative work, and social constructionist views of technology use. This dissertation is a contribution to the assessment of technology use in social settings, particularly in organizations where tasks are often interrupted and a reliance on electronic communication tools impacts how people manage and accomplish work. / text

This thesis investigates new ways of using information visualization to support collaboration in co-located work. To study this phenomenon, Multiple Viewer Display Environments (MVDEs) with independent views have been applied to present information such that all viewers at the same time and in the same display can see correct views of 3D models, see correctly oriented text and see different parts and aspects of information in each view. Several prototypes have been developed either as proof of new conceptual designs or to evaluate particular research questions. These prototypes have been used to investigate general properties that apply to co-located collaborative visualizations. A prototype system to keep track of the viewpoints and information in the independent views was implemented on MVDE hardware to support discussions on future command and control environments and to provide the necessary framework for conducting empirical studies (Paper II). Another prototype, the in situ tomographic display, was developed to support presentation of spatial 3D data (e.g., temperature or airflow) in 2D views in situ with working environments (Paper III). In addition to the visualization systems, a technique for high precision pen-based interaction in rear-projection display environments - the PixelActiveSurface – was developed (Papers IV and V). The empirical studies evaluate how new forms of visualization in MVDEs with independent views affect the way information is perceived and can be shared in collaboration. The conclusion is that multiple independent views can provide more effective and efficient visualization when the following conditions are met: text is oriented towards the viewer (Paper VI), different aspects of information are coordinated between different views of the same display (Paper VIII) and correct views of 3D models are used to compare ordinal information and relations in spatial data (Paper VII). However, for the techniques to support co-located work efficiently, it is necessary that the type of work and the task to be solved are first properly analyzed and understood (Papers VII and IX).

Video-mediated communication (VMC) is currently the prevalent mode of telecommunication for applications such as remote collaboration, teleconferencing, and distance learning. It is generally assumed that transmitting real-time talking-head videos of participants in addition to their audio is beneficial and desirable, enabling remote conferencing to feel almost the same as face-to-face collaboration. However, compared to being face-to-face, VMC still feels distant, artificial, cumbersome, and detached. One limitation of standard video-collaboration that contributes to this feeling is that the 3D context between people and their shared workspace given in face-to-face collaboration is lost. It is therefore not possible for participants to tell from the video what others are looking at, what they are working on, or who they are talking to. Video Collaborative Virtual Environments (video-CVEs) are novel VMC interfaces which address these problems by re-introducing a virtual 3D context into which distant users are mentally "transported" to be together and interact with the environment and with each other, represented by their spatially controllable video-avatars. To date, research efforts following this approach have primarily focused on the demonstration of working prototypes. However, maturation of these systems requires a deeper understanding of human factors that emerge during mediated collaborative processes. This thesis contributes to a deeper understanding of human factors. It investigates the hypothesis that video-CVEs can effectively support face-to-face aspects of collaboration which are absent in standard video-collaboration. This hypothesis is tested in four related comparative user studies involving teams of participants collaborating in video-CVEs, through standard video-conferencing systems, and being face-to-face. The experiments apply and extend methods from the research fields of human-computer interaction, computer-supported cooperative work, and presence. Empirical findings indicate benefits of video-CVEs for user experience dimensions such as social presence and copresence, but also highlight challenges for awareness and usability that need to be overcome to unlock the full potential of this type of interface.

Webcasts are an emerging technology enabled by the expanding availability and capacity of the World Wide Web. This has led to an increase in the number of lectures and academic presentations being broadcast over the Internet. Ideally, repositories of such webcasts would be used in the same manner as libraries: users could search for, retrieve, or browse through textual information. However, one major obstacle prevents webcast archives from becoming the digital equivalent of traditional libraries: information is mainly transmitted and stored in spoken form. Despite voice being currently present in all webcasts, users do not benefit from it beyond simple playback. My goal has been to exploit this information-rich resource and improve webcast users' experience in browsing and searching for specific information. I achieve this by combining research in Human-Computer Interaction and Automatic Speech Recognition that would ultimately see text transcripts of lectures being integrated into webcast archives. In this dissertation, I show that the usefulness of automatically-generated transcripts of webcast lectures can be improved by speech recognition techniques specifically addressed at increasing the accuracy of webcast transcriptions, and the development of an interactive collaborative interface that facilitates users' contributions to machine-generated transcripts. I first investigate the user needs for transcription accuracy in webcast archives and show that users' performance and transcript quality perception is affected by the Word Error Rate (WER). A WER equal to or less than 25% is acceptable for use in webcast archives. As current Automatic Speech Recognition (ASR) systems can only deliver, in realistic lecture conditions, WERs of around 45-50%, I propose and evaluate a webcast system extension that engages users to collaborate in a wiki manner on editing imperfect ASR transcripts. My research on ASR focuses on reducing the WER for lectures by making use of available external knowledge sources, such as documents on the World Wide Web and lecture slides, to better model the conversational and the topic-specific styles of lectures. I show that this approach results in relative WER reductions of 11%. Further ASR improvements are proposed that combine the research on language modelling with aspects of collaborative transcript editing. Extracting information about the most frequent ASR errors from user-edited partial transcripts, and attempting to correct such errors when they occur in the remaining transcripts, can lead to an additional 10 to 18% relative reduction in lecture WER.

Universiẗat, Diss., 2006 u.d.T.: Menold, Natalja: Wissensintegration als eine Voraussetzung des Handelns in Gruppen und ihre Förderung im Kontext der computerunterstützten Kooperation.--Dortmund.

Zugl.: Hildesheim, Universiẗat, Diss., 2007.