OFICINA DE EJECUCION COACTIVA

The Harmonic Walk Interface test have been organized to verify the impact on users perfor- mances of the interface spatial organization and of the interaction modality connected to the active floor or to the touch screen interface. The first experimental hypothesis is that the chord spatial organisation deriving from theoretical and perceptual basis (arrangement 1) works bet- ter than an arrangement that completely disrupts arrangement 1 principles and causes a major physical effort to the user (arrangement 2). Experimental data are clearly contrary to the exper- imental hypothesis as subjects performed much better in arrangement 2 than in arrangement 1, in spite of the major effort required. This result does not refute chord arrangement 1, but rather points out the role of physical effort in subjects memory and performance. It seems that the ma- jor effort required has been able to arouse subjects attention on the movement pattern, allowing thus a better result. Nevertheless, also musical perception plays a role, as shown in some cases by the peaks recorded in the changes between the main and the parallel chord area. The sec- ond experimental hypothesis concerns the difference between the interaction on the active floor surface and on the touch screen, whereas the first is assumed to be more effective on subjects memory and performance. Also in this case the experimental hypothesis has not been confirmed, because subjects performed a little better in the touch than in the full-body condition. Some subjects affirmed that the touch screen was much easier than the active floor, and that this was the reason of their preference. Undoubtedly the touch screen interaction is more precise than the

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active floor and, moreover, users in general are much more accustomed to the touch screen rather than to full-body interaction. On the other hand, this results resonate with those obtained by Johnson-Glenberg et al. (2011), who did not get any significant learning improvement in com- paring physical interaction in the SMALLab environment and traditional mouse and computer screen interaction.1

8.4.1

Consequences for Application Design

The experimental results exposed above help to clarify some important design principles for ac- tive floors applications. The first test result was completely unexpected and probably represents only a hint of how full-body interaction influences users in environments like Harmonic Walk. The world of full-body human computer interaction claims for discovery, and deeper investiga- tion is still needed to understand how it works. On the other hand touch screen interaction seems to be more successful than full-body interaction, though reactive floors have much more facilities than touch screens. Some of them are the following:

1. Reactive floors allow a wider audience participation. Application design has to consider the importance of social interaction as a fundamental design element. The possibility of sharing a common experience with co-located users or with simple by-standers can make an important difference in the learning experience. The common search of problem solutions as well as the sharing of trials and efforts can reinforce cognitive processes and group socialization.

2. Reactive floors can provide an augmented reality immersive environment. In the present Harmonic Walk tests the environment responsiveness has been limited to audio and to very basic graphical elements. Nonetheless, the combination of interactive audio and graphics can provide a much powerful immersive experience which can engage users in a much more convincing way.

3. Reactive floors can become invisible and allow interesting discovery walks. Contrary to immersiveness, reactive floors can be embedded in public spaces and completely disappear to the user’s sight. Thus reactive floors can deploy all the magic of a discovery walk, where users are not aware of being tracked and consequently do not expect any reaction from the system.

Future research on active floor applications needs to be re-defined on the basis of these fun- damental emerging points which enhance the characteristics of responsive environments with respect to touch screens.

Chapter 9

Conclusion

The main purpose of the present thesis is to show how abstract knowledge can be conveyed to the user through spatial representations. Interactive spaces, designed according to the landmarks arrangement that derives from musical concept’s spatial representation, are employed to allow the user to actually enter the active regions and act inside them. Her/his movements are ruled by precise time and space constraints that derive from the musical structure. Thus, user’s move- ment are the expression of the concepts themselves. They are in the same time the measure of the user’s knowledge and the means by which s/he can increase it. In the interactive space ev- erything is mediated by movement and particularly by its direction and timings. The direction depends on the user’s spatial cognition and conceptual map of the interactive environment; the timing depends on user’s cognition and synchronization to musical events. Five case studies de- voted to music learning, active listening and interactive composition and expressive performance are presented. The design principles upon which the music applications are based are summa- rized in a common general framework, which explains the relationship between the application’s musical content and the interactive landmarks or thresholds spatial arrangement. The interac- tion paradigm focuses on the active surface or three-dimensional regions where the user’s moves following the audio and visual feedback produced by the system. Assessment session results show that musical abstract knowledge can actually reach also untrained users and allow them to accomplish complex tasks like melody harmonization. A certain amount of musical knowledge and awareness of the employed musical concepts is achieved by test subjects, also if no addi- tional musical information is provided. Notwithstanding, subjects who could gain some insight about the musical features were not successful in the harmonization task and vice versa, show- ing that embodied knowledge and musical features awareness seem to travel on different tracks. Moreover, subjects who received both information about the musical features and a demonstra- tion of the movement pattern necessary for the harmonization task improved their performance only with respect to the latter, showing the importance of pattern imitation. Further tests on the Harmonic Walk interface seem to suggest that physical effort also plays a role in movement pattern performance. However, if the same task has to be performed on an active floor and on a touch screen surface, users prefer the latter and perform better in the touch modality than in the full-body. All these data point out that full-body interaction is completely different from other forms of physical interaction like touch or point. It is a powerful interaction means that has its

130 Interactive Spaces: Models for Motion-based Music Applications

own rules. It is more sensitive to enactive learning than to explicit information; it is influenced by physical effort and it is not necessarily linked to conceptual awareness; it is extremely ap- pealing mainly for young users who consider full-body interaction as one of the most engaging technological games.