An intuitive model of perceptual grouping for HCI design

ABSTRACT Understanding and exploiting the abilities of the human visual system is an important part of the design of usable user interfaces and information visualizations. Good design enables quick, easy and veridical perception of key components of that design. An important facet of human vision is its ability to seemingly effortlessly perform "perceptual organization"; it transforms individual feature estimates into perception of coherent regions, structures, and objects. We perceive regions grouped by proximity and feature similarity, grouping of curves by good continuation, and grouping of regions of coherent texture. In this paper, we discuss a simple model for a broad range of perceptual grouping phenomena. It takes as input an arbitrary image, and returns a structure describing the predicted visual organization of the image. We demonstrate that this model can capture aspects of traditional design rules, and predicts visual percepts in classic perceptual grouping displays

The relation between school leadership from a distributed perspective and teachers' organizational commitment: examining the source of the leadership function

Purpose: In this study the relationship between school leadership and teachers’ organizational commitment is examined by taking into account a distributed leadership perspective. The relation between teachers’ organizational commitment and contextual variables of teachers’ perceptions of the quality and the source of the supportive and supervisory leadership function, participative decision making, and cooperation within the leadership team are examined. Research Design: A survey was set up involving 1,522 teachers from 46 large secondary schools in Flanders (Belgium). Because the data in the present study have an inherent hierarchical structure, that is, teachers are nested into schools, hierarchical linear modeling techniques are applied. Findings: The analyses reveal that 9% of the variance in teachers’ organizational commitment is attributable to differences between schools. Teachers’ organizational commitment is mainly related to quality of the supportive leadership, cooperation within the leadership team, and participative decision making. Who performed the supportive leadership function plays only a marginally significant positive role. The quality of the supervisory leadership function and the role of the leadership team members in this function were not significantly related to teachers’ organizational commitment. Conclusions: The implications of the findings are that to promote teachers’ organizational commitment teachers should feel supported by their leadership team and that this leadership team should be characterized by group cohesion, role clarity, and goal orientedness. Recommendations for further research are provided

The relationship between the perception of distributed leadership in secondary schools and teachers' and teacher leaders' job satisfaction and organizational commitment

This study investigates the relation between distributed leadership, the cohesion of the leadership team, participative decision-making, context variables, and the organizational commitment and job satisfaction of teachers and teacher leaders. A questionnaire was administered to teachers and teacher leaders (n=1770) from 46 large secondary schools. Multiple regression analyses and path analyses revealed that the study variables explained significant variance in organizational commitment. The degree of explained variance for job satisfaction was considerably lower compared to organizational commitment. Most striking was that the cohesion of the leadership team and the amount of leadership support was strongly related to organizational commitment, and indirectly to job satisfaction. Decentralization of leadership functions was weakly related to organizational commitment and job satisfaction

Management of visual clutter in annotated 3D CAD models: A comparative study

The use of annotations in CAD models has been an active area of research because of their ability to connect design information to specific aspects of the model s geometry. The effectiveness of annotations is determined by the ability to clearly communicate information. However, annotations can quickly create clutter and confusion as they increase both in number and complexity. Consequently, efficient interaction and visualization mechanisms become crucial. Despite recent standardizations of procedures for the presentation of textual information in CAD models, no explicit guidelines are available as to how to make annotated models more readable and manageable. In this paper, we present the results of a comparative study of different mechanisms to manage visual clutter in annotated 3D CAD models and offer recommendations based on our findings. Our results show that even basic interaction mechanisms have a substantial impact on user s performanceCamba, J.; Contero, M.; Johnson, M. (2014). Management of visual clutter in annotated 3D CAD models: A comparative study. Lecture Notes in Computer Science. 8518:405-416. doi:10.1007/978-3-319-07626-3_37S4054168518Kajko-Mattsson, M.: The State of Documentation Practice within Corrective Maintenance. In: IEEE International Conference on Software Maintenance, pp. 354–363. IEEE Press, New York (2001)Van De Vanter, M.L.: The Documentary Structure of Source Code. Information and Software Technology 44, 767–782 (2002)Haouari, D., Sahraoui, H., Langlais, P.: How Good is Your Comment? A Study of Comments in Java Programs. In: International Symposium on Empirical Software Engineering and Measurement, pp. 137–146. IEEE Press, New York (2011)ASME Y14.41-2012 Digital Product Definition Data Practices. The American Society of Mechanical Engineers, New York (2012)ISO 16792:2006 Technical Product Documentation – Digital Product Definition Data Practices. Organisation Internationale de Normalisation, Genève, Suisse (2006)Boehm, B., Bayuk, J., Desmukh, A., Graybill, R., Lane, J.A., Levin, A., et al.: Systems 2020 Strategic Initiative. DoD Systems Engineering Research Center. Technical Report, SERC-2010-TR-009 (2010)Quintana, V., Rivest, L., Pellerin, R.: Measuring and Improving the Process of Engineering Change Orders in a Model-Based Definition Context. International Journal of Product Lifecycle Management 6(2), 138–160 (2012)Alducin-Quintero, G., Rojo, A., Plata, F., Hernández, A., Contero, M.: 3D Model Annotation as a Tool for Improving Design Intent Communication: A Case Study on its Impact in the Engineering Change Process. In: ASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, pp. 349–356. ASME, New York (2012)Dorribo-Camba, J., Alducin-Quintero, G., Perona, P., Contero, M.: Enhancing Model Reuse through 3D Annotations: A Theoretical Proposal for an Annotation-Centered Design Intent and Design Rationale Communication. In: ASME International Mechanical Engineering Congress & Exposition. ASME, New York (2013)Ding, L., Davies, D., McMahon, C.: Sharing Information throughout a Product Lifecycle via Markup of Product Models. In: ASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, pp. 1267–1275. ASME, New York (2008)Ding, L., Ball, A., Patel, M., Matthews, J., Mullineux, G.: Strategies for the Collaborative Use of CAD Product Models. In: Proceedings of ICED 2009, 17th International Conference on Engineering Design, vol. 8, pp. 123–134 (2009)Ding, L., Davies, D., McMahon, C.A.: The Integration of Lightweight Representation and Annotation for Collaborative Design Representation. Research in Engineering Design 20(3), 185–200 (2009)Boujut, J.F., Dugdale, J.: Design of a 3D Annotation Tool for Supporting Evaluation Activities in Engineering Design. Cooperative Systems Design 6, 1–8 (2006)Bracewell, R.H., Wallace, K.M.: A Tool for Capturing Design Rationale. In: 14th International Conference on Engineering Design. Paper no. DS31_1437FPB (2003)Patel, M., Ball, A., Ding, L.: Curation and Preservation of CAD Engineering Models in Product Lifecycle Management. In: 14th International Conference on Virtual Systems and Multimedia Dedicated to Digital Heritage, pp. 59–66 (2008)Li, C., McMahon, C., Newnes, L.: Annotation in Product Lifecycle Management: A Review of Approaches. In: ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, pp. 797–806 (2009)Ahlberg, C., Shneiderman, B.: Visual Information Seeking: Tight Coupling of Dynamic Query Filters with Starfield Displays. In: SIGCHI Conference on Human Factors in Computing Systems, pp. 313–317 (1994)Fishkin, K., Stone, M.C.: Enhanced Dynamic Queries via Movable Filters. In: SIGCHI Conference on Human Factors in Computing Systems, pp. 415–420 (1995)Noyes, L.: The Positioning of Type on Maps: The Effect of Surrounding Material on Word Recognition Time. Human Factors 22(3), 353–360 (1980)Rosenholtz, R., Li, Y., Mansfield, J., Jin, Z.: Feature Congestion: A Measure of Display Clutter. In: SIGCHI Conference on Human Factors in Computing Systems, pp. 761–770 (2005)Tufte, E.R.: The Visual Display of Quantitative Information. Graphics Press, Cheshire (1983)Ellis, G., Dix, A.: A Taxonomy of Clutter Reduction for Information Visualisation. IEEE Transactions on Visualization and Computer Graphics 13(6), 1216–1223 (2007)Wolfe, J.M.: Guided Search 2.0: A Revised Model of Visual Search. Psychonomic Bulletin & Review 1(2), 202–238 (1994)Palmer, J.: Set-size Effects in Visual Search: the Effect of Attention is Independent of the Stimulus for Simple Tasks. Vision Research 34, 1703–1721 (1994)Rosenholtz, R.: Search asymmetries? What search asymmetries? Perception & Psychophysics 63(3), 476–489 (2001)Woodruff, A., Landay, J., Stonebraker, M.: Constant Information Density in Zoomable Interfaces. In: Working Conference on Advanced Visual Interfaces, pp. 57–65 (1998)Ellis, G., Bertini, E., Dix, A.: The Sampling Lens: Making Sense of Saturated Visualisations. In: Extended Abstracts on Human Factors in Computing Systems, pp. 1351–1354 (2005)Ellis, G., Dix, A.: Enabling Automatic Clutter Reduction in Parallel Coordinate Plots. IEEE Transactions on Visualization and Computer Graphics 12(5), 717–723 (2006)Frank, A.U., Timpf, S.: Multiple Representations for Cartographic Objects in a Multi-scale Tree – An Intelligent Graphical Zoom. Computers & Graphics 18(6), 823–829 (1994)Cipriano, G., Gleicher, M.: Text Scaffolds for Effective Surface Labeling. IEEE Transactions on Visualization and Computer Graphics 14(6), 1675–1682 (2008)Stein, T., Décoret, X.: Dynamic Label Placement for Improved Interactive Exploration. In: 6th International Symposium on Non-Photorealistic Animation and Rendering, pp. 15–21 (2008)Ali, K., Hartmann, K., Strothotte, T.: Label Layout for Interactive 3D Illustrations. Journal of WSCG 13(1), 1–8 (2005)Götzelmann, T., Hartmann, K., Strothotte, T.: Agent-Based Annotation of Interactive 3D Visualizations. In: Butz, A., Fisher, B., Krüger, A., Olivier, P. (eds.) SG 2006. LNCS, vol. 4073, pp. 24–35. Springer, Heidelberg (2006

Object Detection Through Exploration With A Foveated Visual Field

We present a foveated object detector (FOD) as a biologically-inspired alternative to the sliding window (SW) approach which is the dominant method of search in computer vision object detection. Similar to the human visual system, the FOD has higher resolution at the fovea and lower resolution at the visual periphery. Consequently, more computational resources are allocated at the fovea and relatively fewer at the periphery. The FOD processes the entire scene, uses retino-specific object detection classifiers to guide eye movements, aligns its fovea with regions of interest in the input image and integrates observations across multiple fixations. Our approach combines modern object detectors from computer vision with a recent model of peripheral pooling regions found at the V1 layer of the human visual system. We assessed various eye movement strategies on the PASCAL VOC 2007 dataset and show that the FOD performs on par with the SW detector while bringing significant computational cost savings.Comment: An extended version of this manuscript was published in PLOS Computational Biology (October 2017) at https://doi.org/10.1371/journal.pcbi.100574

Integration and disruption effects of shape and texture in haptic search

In a search task, where one has to search for the presence of a target among distractors, the target is sometimes easily found, whereas in other searches it is much harder to find. The performance in a search task is influenced by the identity of the target, the identity of the distractors and the differences between the two. In this study, these factors were manipulated by varying the target and distractors in shape (cube or sphere) and roughness (rough or smooth) in a haptic search task. Participants had to grasp a bundle of items and determine as fast as possible whether a predefined target was present or not. It was found that roughness and edges were relatively salient features and the search for the presence of these features was faster than for their absence. If the task was easy, the addition of these features could also disrupt performance, even if they were irrelevant for the search task. Another important finding was that the search for a target that differed in two properties from the distractors was faster than a task with only a single property difference, although this was only found if the two target properties were non-salient. This means that shape and texture can be effectively integrated. Finally, it was found that edges are more beneficial to a search task than disrupting, whereas for roughness this was the other way round

General models in min-max continous location

In this paper, a class of min-max continuous location problems is discussed. After giving a complete characterization of th stationary points, we propose a simple central and deep-cut ellipsoid algorithm to solve these problems for the quasiconvex case. Moreover, an elementary convergence proof of this algorithm and some computational results are presented