Student compliance with ethical guidelines: the Glasgow ethics code

While disciplines like medicine and psychology have for several years followed strict procedures for ethical approval of experiments involving humans, only recently has the use of human participants within Computing Science been subject to the same scrutiny. Although we may wish to put a case forward for Computing Science to be exempt from such formal ethics procedures, funding bodies and universities typically insist that we seek the same approval as other disciplines for our experiments, including any use of human participants by our students during the course of their studies. We have introduced a simple, scalable ethics procedure for student assessment, that identifies ethical concerns, yet does not overwhelm the limited staff resources available for supporting this initiative. The process is based around a form of triage that filters the approximately 8000 assessments that are submitted annually. This paper summarises this procedure, discusses the underlying assumptions, and outlines the problems encountered

Multidimensional tactons for non-visual information presentation in mobile devices

Tactons are structured vibrotactile messages which can be used for non-visual information presentation when visual displays are limited, unavailable or inappropriate, such as in mobile phones and other mobile devices. Little is yet known about how to design them effectively. Previous studies have investigated the perception of Tactons which encode two dimensions of information using two different vibrotactile parameters (rhythm and roughness) and found recognition rates of around 70. When more dimensions of information are required it may be necessary to extend the parameter-space of these Tactons. Therefore this study investigates recognition rates for Tactons which encode a third dimension of information using spatial location. The results show that identification rate for three-parameter Tactons is just 48, but that this can be increased to 81 by reducing the number of values of one of the parameters. These results will aid designers to select suitable Tactons for use when designing mobile displays

A first investigation into the effectiveness of Tactons

This paper reports two experiments relating to the design of Tactons (or tactile icons). The first experiment investigated perception of vibro-tactile "roughness" (created using amplitude modulated sinusoids), and the results indicated that roughness could be used as a parameter for constructing Tactons. The second experiment is the first full evaluation of Tactons, and uses three values of roughness identified in the first experiment, along with three rhythms to create a set of Tactons. The results of this experiment showed that Tactons could be a successful means of communicating information in user interfaces, with an overall recognition rate of 71%, and recognition rates of 93% for rhythm and 80% for roughness

A Coloring Algorithm for Disambiguating Graph and Map Drawings

Drawings of non-planar graphs always result in edge crossings. When there are many edges crossing at small angles, it is often difficult to follow these edges, because of the multiple visual paths resulted from the crossings that slow down eye movements. In this paper we propose an algorithm that disambiguates the edges with automatic selection of distinctive colors. Our proposed algorithm computes a near optimal color assignment of a dual collision graph, using a novel branch-and-bound procedure applied to a space decomposition of the color gamut. We give examples demonstrating the effectiveness of this approach in clarifying drawings of real world graphs and maps

Tactile crescendos and sforzandos: applying musical techniques to tactile icon design

Tactile icons (Tactons) are structured vibrotactile messages which can be used for non visual information display. Information is encoded in Tactons by manipulating vibrotactile parameters. This research investigates the possibilities of applying musical techniques to tactile icon design in order to define such parameters. Tactile versions of musical dynamics were created by manipulating the amplitude of vibrations to create increasing, decreasing, and level stimuli and an experiment was carried out to test perception of these stimuli. Identification rates of 92%-100% indicate that these tactile dynamics can be identified and distinguished from each other, and that tactile dynamics could be used in Tacton design

Octilinear Force-Directed Layout with Mental Map Preservation for Schematic Diagrams

We present an algorithm for automatically laying out metro map style schematics using a force-directed approach, where we use a localized version of the standard spring embedder forces combined with an octilinear magnetic force. The two types of forces used during layout are naturally conflicting, and the existing method of simply combining these to generate a resultant force does not give satisfactory results. Hence we vary the forces, emphasizing the standard forces in the beginning to produce a well distributed graph, with the octilinear forces becoming prevalent at the end of the layout, to ensure that the key requirement of line angles at intervals of 45? is obtained. Our method is considerably faster than the more commonly used search-based approaches, and we believe the results are superior to the previous force-directed approach. We have further developed this technique to address the issues of dynamic schematic layout. We use a Delaunay triangulation to construct a schematic “frame”, which is used to retain relative node positions and permits full control of the level of mental map preservation. This technique is the first to combine mental map preservation techniques with the additional layout criteria of schematic diagrams. To conclude, we present the results of a study to investigate the relationship between the level of mental map preservation and the user response time and accuracy

Stress-Minimizing Orthogonal Layout of Data Flow Diagrams with Ports

We present a fundamentally different approach to orthogonal layout of data flow diagrams with ports. This is based on extending constrained stress majorization to cater for ports and flow layout. Because we are minimizing stress we are able to better display global structure, as measured by several criteria such as stress, edge-length variance, and aspect ratio. Compared to the layered approach, our layouts tend to exhibit symmetries, and eliminate inter-layer whitespace, making the diagrams more compact

Evolutionary Meta Layout of Graphs

A graph drawing library is like a toolbox, allowing experts to select and configure a specialized algorithm in order to meet the requirements of their diagram visualization application. However, without expert knowledge of the algorithms the potential of such a toolbox cannot be fully exploited. This gives rise to the question whether the process of selecting and configuring layout algorithms can be automated such that good layouts are produced. In this paper we call this kind of automation "meta layout." We propose a genetic representation that can be used in meta heuristics for meta layout and contribute new metrics for the evaluation of graph drawings. Furthermore, we examine the use of an evolutionary algorithm to search for optimal solutions and evaluate this approach both with automatic experiments and a user study. The results confirm that our methods can actually help users to find good layout configurations

Exploring the effects of colouring graph diagrams on people of various backgrounds

Colour is one of the primary aesthetic elements of a visualization. It is often used successfully to encode information such as the importance of a particular part of the diagram or the relationship between two parts. Even so, there are few investigations into the human reading of colour coding on diagrams from the scientific community. In this paper we report on an experiment with graph diagrams comparing a black and white composition with two other colour treatments. We drew our subjects from engineering, art, visual design, physical education, tourism, psychology and social science disciplines. We found that colouring the nodes of interest reduced the time taken to find the shortest path between the two nodes for all subjects. Engineers, tourism and social scientists proved significantly faster with artist/designers just below the overall average speed. From this study, we contribute that adding particular colour treatments to diagrams increases legibility. In addition, preliminary work investigating colour treatments and schemes indicates potential for future gains. © 2014 Springer-Verlag