1 The case of sculpting atmospheres: towards design principles for expressive tangible interaction in control of ambient systems Pers Ubiquit Comput (2007) Philip Ross Department of Industrial Design, Eindhoven University of Technology David V. Keyson Faculty of Industrial Design Engineering, Delft University of Technology

2 Outline Introduction Design principles for an expressive tangible interface Case study Conclusions and reflection on design principles

3 Introduction (1/4) This paper focuses on :  Tangible expressive interaction as one possible approach towards linking everyday experiences to intuitive forms of interaction.  Presenting a number of principles for expressive interaction design in this field.

4 Introduction (2/4) From ‘use to presence’ What is a use perspective? Ex: Dialing, ringing, opening an audio channel. → functional aspects of a system or device

5 Introduction (3/4) From ‘use to presence’ What is a presence perspective? Ex: Mobile communication technology offers a feeling of social connectivity.

6 Introduction (4/4) From task-oriented to experience driven design  Most of the ambient systems have a display-only function and do not offer the user with a level of interactive control on the input side. More creativity and personal expression are fostered.

7 Design principles for an expressive tangible interface (1/5) Map and relate human expressiveness to physical interaction possibilities 1. Understand what a person may wish to express via the interface, given common descriptive dimensions. 2. Devise a model that allows a computational system to describe the human expressiveness.

8 Design principles for an expressive tangible interface (2/5) 3. Design physical interaction possibilities that allow a person to express the relevant expressive dimensions. 4. Design a model to interpret the expressive behavior elicited by the physical device. Map and relate human expressiveness to physical interaction possibilities

9 Design principles for an expressive tangible interface (3/5) Capitalize on the expressiveness of form, materials and movement  Physical objects can have a rich variety of expressive properties, such as weight, texture and elasticity. close it gently slam it shut

10 Design principles for an expressive tangible interface (4/5) Make actual experience pivotal in the design process  Real-life ‘experiential’ testing is crucial to learn how design decisions may influence the interaction experience of people.

11 Design principles for an expressive tangible interface (5/5) Consider the subjective nature of expression In ambient systems, subjectivity is salient in two ways: 1.An individual’s experience of the ambient system’s output is subjective. 2. The expressive input of individuals needs to be interpreted by the system, taking individual differences into account.

12 Case study (1/11) An expressive tangible living room atmosphere controller

13 Case study (2/11) Design steps Step 1: atmosphere scaling  Subjects judged mood boards of atmospheres along 13 dimensions in a semantic differential experiment.  Results of a factor analysis yielded three primary factors: 1. Activity level 2. Warmth level 3. Attention level

14 Case study (3/11) Step 2: create a functional atmosphere projection system Arrange video-art, light and music

15 Case study (4/11) Step 3: gesturing workshop

16 Case study (5/11) Step 4: development of interface through mock-ups and user evaluation

17 Case study (6/11) Step 5: Design and build a fully functional prototype of the expressive tangible interface

18 Case study (7/11)

19 First experiment Case study (8/11) Step 6: conduct user studies involving the functional prototype  Two experiments were conducted using a group of seven adults: 1. Seven basic atmospheres were displayed with 14 subtle variants of each basic atmosphere. 2. Each condition was presented at random. 3. Subjects were instructed to rate each projected atmosphere along 13 semantic scales.

20 Case study (9/11) Second experiment 1. Subjects were asked to use the tangible interface to express the same atmospheres that were presented to them in the first experiment. 2. The flag orientations and the rotation speed were sampled and logged at 25 times per second.

21 Case study (10/11) Results and discussion of experiments  The participants were consistent, since they made similar expressions on the Carrousel for similar atmospheres.  The rotation speed turned out to be the strongest parameter to express an atmosphere dimension (activity).

22 Case study (11/11)  Differences between subjects were found both in their experience of atmospheres in terms of warmth, activity and attention.  Interacting with the Carrousel triggered their imagination and allowed them to be creative.

23 Conclusions and reflection on design principles (1/2) Role of design principles in the case study  The design principles provided guidance, which led to the design of a subjectively perceived innovative interface.  The design principles contributed to both the design decisions and conception of the design process.

24 Conclusions and reflection on design principles (2/2) Reflection on design principles  The design principles mainly focus on creating a context for an interaction experience, rather than focusing on technological issues or ergonomic issues.  They can provide a useful basis for structuring design knowledge, generated through design practice.