A.J. Bouwer

Garp3 - Workbench for Qualitative Modelling and Simulation

Garp3 is a domain independent, multi-platform, qualitative modelling and simulation environment. It allows modellers to articulate and refine their conceptual domain knowledge and analyse this knowledge through simulation. Garp3 has been successfully applied in Ecology and Sustainable Development (SD) and is freely available via (http://www.garp3.org). Garp3 and the NaturNet-Redime Project Ecologists in the NaturNet-Redime project (http://www.naturnet.org) are building qualitative models about sustainable development issues through several case studies. For this purpose the Garp3 workbench for building, simulating, and inspecting qualitative models was developed (Bredeweg e al, 2006). The main goals of the development was making qualitative reasoning technology usable for non-computer scientists by creating a uniform user interface, a diagrammatic visual language for representing model content, and graphical buttons to communicate the available user options and manipulations. Garp3 is implemented in SWI-Prolog (http://www.swi-prolog.org) and seamlessly integrates three previously developed software components: Garp2 for simulating models, Homer for building models, and VisiGarp for inspecting simulation results. To further support the ecologists in their modelling efforts a structured approach to modelling was developed. This framework helps modellers refine their initial ideas, represented in concept maps, into detailed conceptualisations, such as structural models, causal models, and expected model behaviour. The diagrams in the final steps of the framework are close to the actual modelling primitives used to implement qualitative models. The Sketch environment in Garp3 supports modellers with tools to create the required diagrams. These Sketches not only help modellers in creating a model, but also serve as a more general description of the final model for other users of the model. One of the main goals of the NaturNet-Redime project is to create a sustainable development curriculum that allows students to learn about specific issues through qualitative modelling and simulation. To advance this goal the case study models developed in project are being integrated into a single library of sustainability concepts. Students can run and adapt different scenarios, let Garp3 automatically gather the correct knowledge relevant to the simulation and predict the possible outcomes, and analyse the results. To support the integration of the different case study models multiple model support and copy/paste functionality have been added to Garp3. The copying functionality assures that models remain syntactically correct, avoids adding redundant knowledge, preserves existing knowledge, and merges conceptual knowledge in a semantically correct manner as much as possible. The copy functionality also allows modellers to reuse parts of

Towards a structured approach to building qualitative reasoning models and simulations

Successful transfer and uptake of qualitative reasoning technology for modelling and simulation in a variety of domains has been hampered by the lack of a structured methodology to support formalisation of ideas. We present a framework that structures and supports the capture of conceptual knowledge about system behaviour using a qualitative reasoning approach. This framework defines a protocol for representing content that supports the development of a conceptual understanding of systems and how they behave. The framework supports modellers in two ways. First, it structures and explicates the work involved in building models. Second, it facilitates easier comparison and evaluation of intermediate and final results of modelling efforts. We show how this framework has been used in developing qualitative reasoning models about three case studies of sustainable development in different river systems.

Garp3: a new workbench for qualitative reasoning and modelling

Easy to use workbenches for Qualitative Reasoning (QR) and Modelling are virtually nonexistent. This has a limiting effect on the use and uptake of the technology by a larger audience. We present Garp3, a user-friendly workbench that allows modellers to build, simulate, and inspect qualitative models. Garp3 can be used to, discover, capture, and share conceptual knowledge on how systems behave.

Feeling the beat where it counts: fostering multi-limb rhythm skills with the haptic drum kit

This paper introduces a tool known as the Haptic Drum Kit, which employs four computer-controlled vibrotactile devices, one attached to each wrist and ankle. In the applications discussed here, haptic pulses are used to guide the playing, on a drum kit, of rhythmic patterns that require multi-limb co-ordination. The immediate aim is to foster rhythm skills and multi-limb coordination. A broader aim is to systematically develop skills in recognizing, identifying, memorizing, retaining, analyzing, reproducing, and composing polyphonic rhythms. We consider the implications of three different theories for this approach: the work of the music educator Dalcroze (1865-1950 [1]; the entrainment theory of human rhythm perception and production [2,3]; and sensory motor contingency theory [4]. In this paper we report on a design study; and identify and discuss a variety of emerging design issues. The study demonstrates that beginning drummers are able to learn intricate drum patterns from haptic stimuli alone

Vibrobelt: tactile navigation support for cyclists

Tactile displays can be used without demanding the attention from the human visual system, which makes them attractive for use in wayfinding contexts, where visual attention should be directed at traffic and other information in the environment. To investigate the potential of tactile navigation for cyclists, we have designed and implemented Vibrobelt. This belt, worn around the waist, gives waypoint, distance and endpoint information using directional tactile cues. We evaluated Vibrobelt by comparing it to a visual navigation application. Twenty participants were asked to cycle two routes, each route with a different application. We measured the spatial knowledge acquisition and analyzed the visual focus of the participants. We found that Vibrobelt was successful at guiding all participants to their destinations over an unfamiliar route. Participants using Vibrobelt showed a lower error rate for recognizing images from the route than users of the visual system. Users of the visual system were generally navigating faster, and were better at recalling the route, showing a higher contextual route understanding. The endpoint distance encoding was not always correctly interpreted. Future research will improve Vibrobelt by making a clearer distinction between waypoint and endpoint information, and will test users in more complex navigational situations.

Should Music Interaction Be Easy

A fundamental assumption in the fields of human-computer interaction and usability studies is that interfaces should be designed for ease of use, with a few exceptions such as the trade-off with long-term power. In this chapter it is argued that in music interaction the situation is far more complex, with social, technical, artistic, and psychological reasons why difficulty is in some cases a good thing, and in other cases a necessary evil. Different aspects of static and time-varying difficulty in music interaction are categorised. Some specific areas in which difficulty seems to be inextricably linked to positive aspects of music interaction are described. This is followed by discussion of some areas in which difficulty is undesirable and, perhaps, avoidable. Examples are drawn from music interaction research in general and from other chapters of this book in particular.

Whole Body Interaction in Abstract Domains

There is little dispute that Whole Body Interaction is a good fit of interaction style for some categories of application domain, such as the motion capture of gestures for computer games and virtual physical sports. This reflects the observation that in such applications the mapping between user gesture and the desired effect is, broadly speaking, the identity function. For more abstract application areas such as mathematics, programming and musical harmony, finding appropriate mappings between gesture and effect is less straightforward. The creation of appropriate whole body interaction designs for such abstract application areas remains challenging. However, this is not to argue that whole body interaction is unsuited to abstract domains. Indeed, there is evidence, outlined below, that whole body interaction offers excellent affordances for some highly abstract applications areas.

The Haptic Bracelets: Learning Multi-Limb Rhythm Skills from Haptic Stimuli While Reading

The Haptic Bracelets are a system designed to help people learn multi-limbed rhythms (which involve multiple simultaneous rhythmic patterns) while they carry out other tasks. The Haptic Bracelets consist of vibrotactiles attached to each wrist and ankle, together with a computer system to control them. In this chapter, we report on an early empirical test of the capabilities of this system, and consider design implications. In the pre-test phase, participants were asked to play a series of multi-limb rhythms on a drum kit, guided by audio recordings. Participants’ performances in this phase provided a base reference for later comparisons. During the following passive learning phase, away from the drum kit, just two rhythms from the set were silently ‘played’ to each subject via vibrotactiles attached to wrists and ankles, while participants carried out a 30-min reading comprehension test. Different pairs of rhythms were chosen for different subjects to control for effects of rhythm complexity. In each case, the two rhythms were looped and alternated every few minutes. In the final phase, subjects were asked to play again at the drum kit the complete set of rhythms from the pre-test, including, of course, the two rhythms to which they had been passively exposed. Pending analysis of quantitative data focusing on accuracy, timing, number of attempts and number of errors, in this chapter we present preliminary findings based on participants’ subjective evaluations. Most participants thought that the technology helped them to understand rhythms and to play rhythms better, and preferred haptic to audio to find out which limb to play when. Most participants indicated that they would prefer using a combination of haptics and audio for learning rhythms to either modality on its own. Replies to open questions were analysed to identify design issues, and implications for design improvements were considered.

Song Walker Harmony Space: Embodied Interaction Design for Complex Musical Skills

Tonal Harmony is widely considered to be the most technical and complex part of music theory. Consequently harmonic skills can be hard to acquire. Furthermore, experience of the flexible manipulation of harmony in real time generally requires the ability to play an instrument. Even for those with instrumental skills, it can be difficult to gain clear insight into harmonic abstractions. The above state of affairs gives rise to substantial barriers not only for beginners but also for many experienced musicians. To address these problems, Harmony Space is an interactive digital music system designed to give insight into a wide range of musical tasks in tonal harmony, ranging from performance and composition to analysis. Harmony Space employs a principled set of spatial mappings to offer fluid, precise, intuitive control of harmony. These mappings give rise to sensory-motor and music-theoretic affordances that are hard to obtain in any other way. As a result, harmonic abstractions are rendered amenable to concrete, visible control by simple spatial manipulation. In the language of conceptual metaphor theory, many relationships in tonal harmony become accessible to rapid, universal, low-level, robust human inference mechanisms using image schemata such as containment, contact, centre-periphery, and source-path-goal. This process is more rapid, and imposes far less cognitive load, than slow, abstract symbolic reasoning. Using the above principles, several versions of Harmony Space have been designed to exploit specific interaction styles for different purposes. We note some key variants, such as the desktop version, the camera tracked version, while focusing principally on the most recent version, Song Walker, which employs whole body interaction. Preliminary results from a study of the Song Walker system are outlined, in which both beginners and expert musicians undertook a range of musical tasks involving the performance, composition and analysis of music. Finally, we offer a discussion of the limitations of the current system, and outline directions for future work.

Haptics for the Development of Fundamental Rhythm Skills, Including Multi-limb Coordination

This chapter considers the use of haptics for learning fundamental rhythm skills, including skills that depend on multi-limb coordination. Different sensory modalities have different strengths and weaknesses for the development of skills related to rhythm. For example, vision has low temporal resolution and performs poorly for tracking rhythms in real time, whereas hearing is highly accurate. However, in the case of multi-limbed rhythms, neither hearing nor sight is particularly well suited to communicating exactly which limb does what and when, or how the limbs coordinate. By contrast, haptics can work especially well in this area, by applying haptic signals independently to each limb. We review relevant theories, including embodied interaction and biological entrainment. We present a range of applications of the Haptic Bracelets, which are computer-controlled wireless vibrotactile devices, one attached to each wrist and ankle. Haptic pulses are used to guide users in playing rhythmic patterns that require multi-limb coordination. One immediate aim of the system is to support the development of practical rhythm skills and multi-limb coordination. A longer-term goal is to aid the development of a wider range of fundamental rhythm skills including recognising, identifying, memorising, retaining, analysing, reproducing, coordinating, modifying and creating rhythms—particularly multi-stream (i.e. polyphonic) rhythmic sequences. Empirical results are presented. We reflect on related work and discuss design issues for using haptics to support rhythm skills. Skills of this kind are essential not just to drummers and percussionists but also to keyboards’ players and more generally to all musicians who need a firm grasp of rhythm.