| 1. |
- Bivall, Petter, et al.
(författare)
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Haptic Just Noticeable Difference in Continuous Probing of Volume Data
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Just noticeable difference (JND) describes how much two perceptual sensory inputs must differ in order to be distinguishable from each other. Knowledge of the JND is vital when two features in a dataset are to be separably represented. JND has received a lot of attention in haptic research and this study makes a contribution to the field by determining JNDs during users' probing of volumetric data at two force levels. We also investigated whether these JNDs were affected by where in the haptic workspace the probing occurred. Reference force magnitudes were 0.1 N and 0.8 N, and the volume data was presented in rectangular blocks positioned at the eight corners of a cube 10 cm3 in size. Results showed that the JNDs varied significantly for the two force levels, with mean values of 38.5% and 8.8% obtained for the 0.1 N and 0.8 N levels, respectively, and that the JND was influenced by where the data was positioned.
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| 2. |
- Forsell, Camilla
(författare)
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A Guide to Scientific Evaluation in Information Visualization
- 2010
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Ingår i: 14th International Conference Information Visualization IV 2010. - 9781424478460 ; , s. 162-169
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Konferensbidrag (refereegranskat)abstract
- This paper addresses some fundamental and practical issues that should be considered when pursuing evaluation studies in Information Visualization. The main focus is on quantitative experimental research but the general information applies to all kinds of studies. The purpose is to increase awareness of what constitutes a sound scientific approach to evaluation and to point out common pitfalls and mistakes during the phases of such study. These phases cover how to plan, design, conduct and analyse the outcome of an evaluation and finally how to report in a way that enhances readability, provides details relevant to the outcome and that allows replication. The paper could be used as a guide when conducting evaluation and it could also be helpful when reviewing publications since the same rules apply.
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| 3. |
- Forsell, Camilla, et al.
(författare)
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An Heuristic Set for Evaluation in Information Visualization
- 2010
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Ingår i: Advanced Visual Interfaces, AVI10. - New York, USA : ACM press. - 9781450300766 ; , s. 199-206
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Konferensbidrag (refereegranskat)abstract
- Evaluation is a key research challenge within the international Information Visualization (InfoVis) community, and Heuristic Evaluation is one recognized method. Various sets of heuristics have been proposed but there remains no consensus as to which heuristics are most useful for addressing aspects specific to the complex interactive visual displays used in modern InfoVis systems. This paper presents a first effort to empirically determine a new set of such general heuristics tailored for Heuristic Evaluation of common and important usability problems in InfoVis techniques. Participants in the study rated how well a total of 63 heuristics from 6 earlier published heuristic sets could explain a collection of 74 usability problems derived from earlier InfoVis evaluations. The results were used to synthesize 10 heuristics that, as a set, provided the highest explanatory coverage. The paper also stresses the challenges for future research to validate and further improve upon this set.
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| 4. |
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| 5. |
- Forsell, Camilla, et al.
(författare)
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Questionnaires for evaluation in information visualization
- 2012
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Ingår i: BELIV '12 Proceedings of the 2012 BELIV Workshop. - New York : ACM Press. - 9781450317917
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Konferensbidrag (refereegranskat)abstract
- The position taken in this paper is that the availability of standardized questionnaires specifically developed for measuring users' perception of usability in evaluation studies in information visualization would provide the community with an excellent additional instrument. The need for such an instrument is evident for several important reasons. Pursuing the development, validation and use of questionnaires will add significantly to the evidence base necessary for the community to guide the production of high-quality visualization techniques, facilitate adoption by users, promote successful commercialization and guide future research tasks.
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| 6. |
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| 7. |
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| 8. |
- Johansson, Jimmy, et al.
(författare)
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On the usability of three-dimensional display in parallel coordinates: Evaluating the efficiency of identifying two-dimensional relationships
- 2014
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Ingår i: Information Visualization. - : Sage Publications. - 1473-8716 .- 1473-8724. ; 13:1, s. 29-41
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, several different attempts have been made to extend the well-known technique of parallel coordinates using a three-dimensional display. This article presents an evaluation that investigates the performance of the three-dimensional parallel coordinates technique and compares it with standard, two-dimensional parallel coordinates for analysis of two-dimensional relationships. Three-dimensional parallel coordinates, based on parallel planes instead of parallel axes, have been used for many years within the information visualization community for a variety of applications. Despite its quite common use, no formal evaluation detailing its usefulness for different tasks has been conducted. The evaluation presented in this article is the first step towards determining the usefulness of this type of three-dimensional parallel coordinates. The study compared three-dimensional parallel coordinates, using two different axis configurations commonly seen in the literature, with standard two-dimensional parallel coordinates for identification of two-dimensional relationships between variables in multivariate data. This type of task and the relationships to be judged are known to be well supported by two-dimensional parallel coordinates and multi-relational three-dimensional parallel coordinates. The results show that for identification of two-dimensional relationships, two-dimensional parallel coordinates are superior to the three-dimensional extensions, in terms of both response time and accuracy. Subjective opinions were also in favour of two-dimensional parallel coordinates. This study adds to the much-needed body of work examining the usability of three-dimensional representations in information visualization and for what tasks and data a proposed method is or is not appropriate.
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| 9. |
- Kocak, Umut, 1981-, et al.
(författare)
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Analysis of the JND of Stiness in Three Modesof Comparison
- 2011
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Ingår i: HAID'11 Proceedings of the 6th international conference on Haptic and audio interaction design. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 9783642229497 - 9783642229503 ; , s. 22-31
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Understanding and explaining perception of touch is a non-trivial task. Even seemingly trivial differences in exploration may potentially have a significant impact on perception and levels of discrimination. In this study, we explore different aspects of contact related to stiffness perception and their effects on the just noticeable difference (JND) of stiffness are surveyed. An experiment has been performed on non-deformable, compliant objects in a virtual environment with three different types of contact: Discontinuous pressure, continuous pressure and continuous lateral motion. The result shows a significantly better discrimination performance in the case of continuous pressure (a special case of nonlinearity), which can be explained by the concept of haptic memory. Moreover, it is found that the perception is worse for the changes that occur along the lateral axis than the normal axis.
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| 10. |
- Kocak, Umut, 1981-, et al.
(författare)
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The Effect of the Stiffness Gradient on the Just Noticeable Difference between Surface Regions
- 2012
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Ingår i: Haptics: Perception, Devices, Mobility, and Communication. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 9783642314001 - 9783642314018 ; , s. 282-292
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Bokkapitel (refereegranskat)abstract
- This book and its companion volume, LNCS 7282 and 7283, constitute the refereed proceedings of the 8th International Conference, EuroHaptics 2012, held in Tampere, Finland, in June 2012. The 99 papers (56 full papers, 32 short papers, and 11 demo papers) presented were carefully reviewed and selected from 153 submissions. Part I contains the full papers whereas Part II contains the short papers and the demo papers.
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| 11. |
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| 12. |
- Lundberg, Jonas, 1974-, et al.
(författare)
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The Use of Conflict Detection Tools in Air Traffic Management – an Unobtrusive Eye Tracking Field Experiment During Controller Competence Assurance
- 2014
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Ingår i: HCI-Aero 2014 - International Conference on Human-Computer Interaction in Aerospace. - Mountain View, CA, USA : ACM Press.
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Konferensbidrag (refereegranskat)abstract
- This study aims at explaining loss of separation events over the Swedish air space in 2011- 2012, which occurred despite an automated conflict detection tool working as designed. The study suggests that there may be a trade-off between spending visual scan time on own conflict detection versus visual scan time spent on examining potential conflicts presented by the conflict detection automation. The issue is hard to solve, and is unfortunately far from resolved. This area of research requires a substantial applied research effort, if the goal is to both increase safety and capacity of ATM through the use of automation.
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| 13. |
- Lundström, Claes, et al.
(författare)
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Multi-Touch Table System for Medical Visualization: Application to Orthopedic Surgery Planning
- 2011
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Ingår i: IEEE Transactions on Visualization and Computer Graphics. - : Institute of Electrical and Electronics Engineers (IEEE). - 1077-2626 .- 1941-0506. ; 17:12, s. 1775-1784
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Tidskriftsartikel (refereegranskat)abstract
- Medical imaging plays a central role in a vast range of healthcare practices. The usefulness of 3D visualizations has been demonstrated for many types of treatment planning. Nevertheless, full access to 3D renderings outside of the radiology department is still scarce even for many image-centric specialties. Our work stems from the hypothesis that this under-utilization is partly due to existing visualization systems not taking the prerequisites of this application domain fully into account. We have developed a medical visualization table intended to better fit the clinical reality. The overall design goals were two-fold: similarity to a real physical situation and a very low learning threshold. This paper describes the development of the visualization table with focus on key design decisions. The developed features include two novel interaction components for touch tables. A user study including five orthopedic surgeons demonstrates that the system is appropriate and useful for this application domain.
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| 14. |
- Nguyen, Tan Khoa, et al.
(författare)
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Concurrent Volume Visualization of Real-Time fMRI
- 2010
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Ingår i: Proceedings of the 8th IEEE/EG International Symposium on Volume Graphics. - Goslar, Germany : Eurographics - European Association for Computer Graphics. - 9783905674231 ; , s. 53-60
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Konferensbidrag (refereegranskat)abstract
- We present a novel approach to interactive and concurrent volume visualization of functional Magnetic Resonance Imaging (fMRI). While the patient is in the scanner, data is extracted in real-time using state-of-the-art signal processing techniques. The fMRI signal is treated as light emission when rendering a patient-specific high resolution reference MRI volume, obtained at the beginning of the experiment. As a result, the brain glows and emits light from active regions. The low resolution fMRI signal is thus effectively fused with the reference brain with the current transfer function settings yielding an effective focus and context visualization. The delay from a change in the fMRI signal to the visualization is approximately 2 seconds. The advantage of our method over standard 2D slice based methods is shown in a user study. We demonstrate our technique through experiments providing interactive visualization to the fMRI operator and also to the test subject in the scanner through a head mounted display.
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| 15. |
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| 16. |
- Scandurra, Isabella, 1973-, et al.
(författare)
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Advancing the State-of-the-Art for Virtual Autopsies : Initial Forensic Workflow Study
- 2010
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Ingår i: Studies in Health Technology and Informatics. - : IOS Press. - 0926-9630 .- 1879-8365. ; 160, s. 639-643
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Tidskriftsartikel (refereegranskat)abstract
- There are numerous advantages described of how imaging technology can support forensic examinations. However, postmortem examinations of bodies are mainly performed to address demands which differ from those of traditional clinical image processing. This needs to be kept in mind when gathering information from image data sets for forensic purposes. To support radiologists and forensicclinicians using Virtual Autopsy technologies, an initial workflow study regarding post-mortem imaging has been performed, aiming to receive an improved understanding of how Virtual Autopsyworkstations, image data sets and processes can be adjusted to support and improve conventional autopsies. This paper presents potential impacts and a current forensic Virtual Autopsy workflowaiming to form a foundation for collaborative procedures that increase the value of Virtual Autopsy. The workflow study will provide an increased and mutual understanding of involved professionals. In addition, insight into future forensic workflows based on demands from both forensic and radiologist perspectives bring visualization and medical informatics researchers together to develop and improvethe technology and software needed.
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| 17. |
- Tominski, Christian, et al.
(författare)
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Interaction Support for Visual Comparison Inspired by Natural Behavior
- 2012
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Ingår i: IEEE Transactions on Visualization and Computer Graphics. - : Institute of Electrical and Electronics Engineers (IEEE). - 1077-2626 .- 1941-0506. ; 18:12, s. 2719-2728
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Tidskriftsartikel (refereegranskat)abstract
- Visual comparison is an intrinsic part of interactive data exploration and analysis. The literature provides a large body of existing solutions that help users accomplish comparison tasks. These solutions are mostly of visual nature and custom-made for specific data. We ask the question if a more general support is possible by focusing on the interaction aspect of comparison tasks. As an answer to this question, we propose a novel interaction concept that is inspired by real-world behavior of people comparing information printed on paper. In line with real-world interaction, our approach supports users (1) in interactively specifying pieces of graphical information to be compared, (2) in flexibly arranging these pieces on the screen, and (3) in performing the actual comparison of side-by-side and overlapping arrangements of the graphical information. Complementary visual cues and add-ons further assist users in carrying out comparison tasks. Our concept and the integrated interaction techniques are generally applicable and can be coupled with different visualization techniques. We implemented an interactive prototype and conducted a qualitative user study to assess the concepts usefulness in the context of three different visualization techniques. The obtained feedback indicates that our interaction techniques mimic the natural behavior quite well, can be learned quickly, and are easy to apply to visual comparison tasks.
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| 18. |
- Vrotsou, Katerina, 1980-, et al.
(författare)
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2D and 3D Representations for Feature Recognition in Time Geographical Diary Data
- 2010
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Ingår i: Information Visualization. - : Palgrave Macmillan Ltd. - 1473-8716 .- 1473-8724. ; 9:4, s. 263-276
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Tidskriftsartikel (refereegranskat)abstract
- Time geographical representations are becoming a common approach to analysing spatio-temporal data. Such representations appear intuitive in the process of identifying patterns and features as paths of populations form tracks through the 3D space, which can be seen converging and diverging over time. In this article, we compare 2D and 3D representations within a time geographical visual analysis tool for activity diary data. We identify a representative task and evaluate task performance between the two representations. The results show that the 3D representation has benefits over the 2D representation for feature identification but also indicate that these benefits can be lost if the 3D representation is not carefully constructed to help the user to see them.
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| 19. |
- Vrotsou, Katerina, et al.
(författare)
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A Qualitative Study of Similarity Measures in Event-Based Data
- 2011
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Ingår i: Human Interface and the Management of Information. Interacting with Information. - Berlin/Heidelberg : Springer. - 9783642217920 - 9783642217937 ; , s. 170-179
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Bokkapitel (refereegranskat)abstract
- This paper presents an interview-based study of the definition of sequence similarity in different application areas of event-based data. The applicability of nine identified measures across these areas is investigated and discussed. The work helps highlight what are the core characteristics sought when analysing event-based data and performs a first validation of this across disciplines. The results of the study make a solid basis for follow-up evaluations of the practical applicability and usability of the similarity measures.
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