Commonly attributed smart home challenges for both primary and secondary users have been researched extensively, yet there is a gap in understanding mental models and their influence on how both types of users internalize and domesticate smart home lighting systems including bulbs, lamps, smart plugs, switches, and presence sensors. Our study targets the perceptual distinction between both users from a long-term domestication perspective. We conducted an in-situ ethnographic study with 12 households in the Netherlands and a subsequent online survey with 93 participants. Our research offers three contributions. By analyzing guided diaries, interviews, and surveys, we characterize the intricate mental models (spatial, contextual, functional, and metaphorical mapping) within and across households. Second, we addressed the distinctiveness and importance of the post-domestication phase in smart home lighting systems. Lastly, we present design recommendations to improve future smart home system designs aimed at long-term, evolving use.

It has been shown that providing explanations about AI-based systems’ decisions can be an effective way to increase users’ trust and acceptance. The effect of explanation design in smart home systems on users’ acceptance and perceptions is however less known. We therefore explored the effect of different explanation designs on acceptance in the context of the Philips Hue smart home lighting system. We conducted interviews (N = 10) and an online experiment (N = 452) using three everyday smart home lighting scenarios with different explanation types. The results showed that although participants indicated a positive attitude towards explanations, receiving an explanation can potentially reduce the perceived control of the lighting system. Furthermore, participants preferred system-based explanations rather than user-based explanations. Our study also provides recommendations for the design of explanations in smart home systems.

In this paper we report on an exploration of how to apply the theory of Slow Design to mass produced products to establish more mindful usage of products; the intention behind this is to promote product attachment and the associated sustainable benefits of long term use. Slow Design is a design philosophy that focuses on promoting well-being for individuals, society, and the natural environment. It encourages people to do things at the right time and at the right speed which helps them to understand and reflect on their actions. Several authors have proposed Slow Design principles and cases have been reported in which these principles were applied in cultural design projects. These applications indicated that Slow Design can indeed have a positive impact on wellbeing. Although promising, this philosophy has not yet been used in the design of mass consumer products. In this paper we present a design case study in which we explored how the Slow Design principles can be applied in the design of an electric fruit juicer. Two studies are reported on where the conditions for implementing Slow Design are explored. The results led to a revision of the principles for use by product designers. The main finding from the case study is that the Slow Design principles can be used to create more 'mindful' interactions that stimulate positive user involvement. This is not from designing interactions that require more time per se, but by stimulating the user to use more time for those parts of the interaction that are meaningful and less for those that are not meaningful.

LED-based lighting systems have introduced radically new possibilities in the area of artificial lighting. Being physically small the LED can be positioned or embedded into luminaires, materials and even the very fabric of a building or environment. Hundreds of LEDs can be used in a single luminaire or space, of which each could have different light output properties. The light switch therefore in many situations will need to be enhanced or fully replaced by intelligent controls and smart environments that are sensitive to the context and responsive to the people in the environment. The focus of this workshop is to explore new ways of interacting with light where lighting is no longer simply an on or off system, but a flexible system capable of creating a large range of functional, decorative and ambient light effects.

The current paper proposes a novel method of analyzing goal-directed movements by dividing them into distinct movement intervals. We demonstrate how the description of the first and second most prominent movement intervals in terms of duration and length can provide insight into the applied movement strategies under different conditions. This method, although demonstrated for goal-directed movements, has the potential to be generalized to other types of movements, such as steering movements.

Multi-display environments (MDEs) are now becoming common, and are becoming more complex, with more displays and more types of display in the environment. One crucial requirement specific to MDEs is that users must be able to move objects from one display to another; this cross-display movement is a frequent and fundamental part of interaction in any application that spans two or more display surfaces. Although many cross-display movement techniques exist, the differences between MDEs—the number, location, and mixed orientation of displays, and the characteristics of the task they are being designed for—require that interaction techniques be chosen carefully to match the constraints of the particular environment. As a way to facilitate interaction design in MDEs, we present a taxonomy that classifies cross-display object movement techniques according to three dimensions: the referential domain that determines how displays are selected, the relationship of the input space to the display configuration, and the control paradigm for executing the movement. These dimensions are based on a descriptive model of the task of cross-display object movement. The taxonomy also provides an analysis of current research that designers and researchers can use to understand the differences between categories of interaction techniques.

A plethora of reaching techniques, intended for moving objects between locations distant to the user, have recently been proposed and tested. One of the most promising techniques is the Radar View. Up till now, the focus has been mostly on how a user can interact efficiently with a given radar map, not on how these maps are created and maintained. It is, for instance, unclear whether or not users would appreciate the possibility of adapting such radar maps to particular tasks and personal preferences. In this paper, we address this question by means of a prolonged user study with the Sketch Radar prototype. The study demonstrates that users do indeed modify the default maps in order to improve interactions for particular tasks. It also provides insights into how and why the default physical map is modified.

A plethora of reaching techniques, intended for moving objects between locations distant to the user, have recently been proposed and tested. One of the most promising techniques is the Radar View. Up till now, the focus has been mostly on how a user can interact efficiently with a given radar map, not on how these maps are created and maintained. It is for instance unclear whether or not users would appreciate the possibility of adapting such radar maps to particular tasks and personal preferences. In this paper we address this question by means of a prolonged user study with the Sketch Radar prototype. The study demonstrates that users do indeed modify the default maps in order to improve interactions for particular tasks. It also provides insights into how and why the default physical map is modified.

In our studies aimed at understanding design practice we have identified the creation of mood boards as a relevant task for designers. In this paper we introduce an interactive wall-mounted display system that supports the presentation of mood boards. The system allows designers to easily record their mood board presentations while capturing the richness of their individual presentation skills and style. Designers and clients can play back, explore and comment on different aspects of the presentation using an intuitive and flexible interaction based on hand gestures thus supporting two-way communication. The system records the presentation and organizes it into three information layers (i.e. gesture, sound and visuals), which are first used to segment the presentation into meaningful parts, and later for playback. Exploratory evaluations show that designers are able to use the system with no prior training, and see a practical use of the proposed system in their design studios.

Multi-flick, which consists of repeated flick actions, has received popular media attention as an intuitive and natural document-scrolling technique for stylus based systems. In this paper we put multi-flick to test, by designing several flick-based scrolling techniques. We first map out the de-sign space of multi-flick and identify mapping functions that make multi-flick a natural and intuitive technique for document navigation. In the first experiment we compare several multi-flick variations for navigating lists on three different devices -- a PDA, a tabletPC, and a large table. Our study shows that compound-multi-flick (CMF) is the most preferred technique and it is at least as fast, if not faster than the traditional scrollbar. In a follow-up experiment, we evaluate multi-flick for scrolling text-based documents. Results show that all implementations of multi-flick are as good as the scrollbar for short distances while CMF is the most preferred. We discuss the implications of our findings and present several design guidelines.

The research on Tangible Interaction (TI) has been inspired by many different disciplines, including psychology, sociology, engineering and human-computer interaction (HCI). Now that the field is getting more mature, in the sense that basic technologies and interaction paradigms have been explored, we observe a growing potential for a more design-oriented research approach. We suggest that there are several arguments for this proposed broadening of the TI-perspective: 1) the need for designing products within contexts-of-use that are much more challenging and diverse than the task-oriented desktop (or tabletop) systems that mostly inspire us today, 2) the interest to also design TI starting from existing physical activities instead of only as add-ons to digital applications, 3) the need for iterative design and evaluation of prototypes in order to develop applications that are grounded within daily practice over prolonged periods of time, and 4) the need to extend ease-of-use to more hedonic aspects of interaction such as fun and engagement

The rapid increase in display sizes and resolutions has led to the re-emergence of many pen-based interaction systems like tabletop and wall display environments. Pointing in these environments is an important task, but techniques have not exploited the manipulation of control and display parameters to the extent seen in desktop environments. We have overcome these in the design of a new pen-based interaction technique -- Bubble Radar. Bubble Radar allows users to reach both specific targets and empty space, and supports dynamic switching between selecting and placing. The technique is based on combining the benefits of a successful pen-based pointing technique, the Radar View, with a successful desktop object pointing technique -- the Bubble Cursor. We tested the new technique in a user study and found that it was significantly faster than existing techniques, both for overall pointing and for targeting specific objects.

Designers and architects regularly use piles to organise visual artifacts. Recent efforts have now made it possible for users to create piles in digital systems as well. However, there is still little understanding of how users shouldinteract with digital piles. In this paper we investigate this issue. We first identify three tasks that must be supported by a digitalpile—navigation, reorganisation and repositioning. We then present three interaction techniques—called HoverDeck, DragDeck and ExpandPile that meet these requirements. The techniques allow users to easily browse the piles, and also allow them to move elements between and within piles in an ad-hoc manner. In a user study that compared the different interaction techniques, we found that ExpandPile was significantly faster than the other techniques over all tasks. There were differences, however, in individual tasks. We discuss the benefits and limitations of the different techniques and identify several situations where each of them could prove useful.

Interaction on digital tables has been restricted to a single layer on the table's active work-surface. We extend the design space of digital tables to include multiple layers of interaction. We leverage 3D position information of a pointing device to support interaction in the space above the active work-surface by creating multiple layers with drift-correction in which the user can interact with an application. We also illustrate through a point-design that designers can use multiple-layers to create a rich and clutter free application. A subjective evaluation showed that users liked the interaction techniques and found that, because of the drift correction we use, they could control the pointer when working in any layer.

Even in the current computer age, there are still many important application areas, such as early architectural design, where traditional tools like sketching on paper continue to be preferred by many professionals over computer-based tools. There is a growing awareness that there are often very good grounds for this preference. Hence, instead of trying to replace such traditional ways of working, it is now often considered more opportune to try and preserve the strengths of these traditional ways of working, while at the same time improving them by providing access to new media. This is one of the main objectives of the augmented reality approach that we adopt here. In this paper, we specifically discuss the realization of a tool for early architectural design on an existing augmented reality system, called the Visual Interaction Platform. We describe the development process, the resulting tool and its performance for elementary tasks such as positioning and overdrawing. We also identify directions for future research and applications.

Recent advances in multi-user collaboration have seen a proliferation of interaction techniques for moving digital objects from one device to another. However, little is known about how these techniques work in realistic situations, or how they compare to one another. We conducted a study to compare the efficiency of six techniques for moving objects from a tablet to a tabletop display. We compared the techniques in four different distance ranges and with three movement directions. We found that techniques like the Radar View and Pick-and-Drop, that have a control-to-display ratio of 1, are significantly faster for object movement than techniques that have smaller control-to-display ratios. We also found that using spatial manipulation of objects was faster than pressure-based manipulation.