Smart Environments

3.3.1 A (Re-) Definition of Smart Environment

Since Weiser’s initial vision of UbiComp (see 2.2.2), researchers coined several other terms that all refer to different aspects of a smart environment, such as Pervasive Computing, Ambient Intelligence, Smart Environments, and Internet of Things (see 2.1). For my dissertation, I felt that none of the existing terms captured the context of my work properly and that using these terms could mislead readers. This is why I decided to provide my own definition of smart

environment: a confined physical space with digital artifacts in it. The only assumptions I make

about a smart environment are that its dimension (size and height) is typical for a domestic room (e.g., kitchen and living room) or an office space (e.g., offices or cubicles) and that people can control digital artifacts remotely, i.e., through a common digital system.

3.3.2 Example Tasks for Command Selection in Smart Environments

An important premise when comparing different interaction techniques for smart environments is that there will not be a single technique that is superior in all potential scenarios. For this, smart environments provide too many different use cases. I want to outline three mundane scenarios in domestic environments to demonstrate this diversity:

1. selecting a movie to watch on TV 2. checking a cooking recipe

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These three scenarios occur daily in homes around the world and feature a non-computer-based main goal or primary task and a UbiComp-based supporting task. When comparing scenarios, I focus on the following aspects: how does the UbiComp interaction fit into the users’ process of reaching their main goal, how complex is the UbiComp interaction, and how large is the input, output, and feedback space? These scenarios also represent the primary tasks that I am focusing on in my dissertation: single action selections. All three tasks can be completed with a single selection.

In the dissertation, I specifically limit HEI to artifact selection, which is choosing a single artifact from a larger group

Selecting a Movie

When watching a movie is the user’s main goal, the supporting UbiComp task of selecting the movie is rather complex as it requires to make a selection between potentially thousands of digital artifacts. All these artifacts have to be displayed, and users need means for browsing or searching. This complexity demands large input and output space and could make the supporting task disruptive of the primary task. The supporting task, however, occurs serial to the primary task because it happens before the primary task and does not coincide with it. As a result, the cost of interruption is relatively low, and the interaction does not have to focus on selection speed.

The user interface should be able to support complex interactions to accommodate the large input and output spaces. Possible solutions are hierarchical menus or a search function, which require display space for output and text entry for input. As a result, a smart phone or tablet would be a suitable interaction device.

Checking a Recipe

The supporting UbiComp task of checking a cooking recipe is simple as it might only require basic functionality, such as scrolling and zooming. Input and output space is therefore smaller than in the example above. The task can, however, overlap with the primary task (cooking) and can occur multiple times. This co-occurrence forces users to switch contexts between the primary task and the supporting task. These context switches can be very time-consuming and disruptive because cooking includes handling fatty, sticky, and potentially pathogenic ingredients that can

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damage touched device or harm people. Device-free interaction would clearly reduce the cost of interruption.

The user interface only has to support a small input space, while providing some means for outputting text and imagery. Given these requirements, smart phones might not be the best-suited interaction device. Instead, a wall-mounted display with gestural input might be more useable. Turning on Lights

Turning on the lights while reading a book is a minimalistic task with small input space and no system feedback. Readers might be deeply immersed in a book when the need for more light arises in order to proceed with the primary task (reading). Given the simple and brief nature of the supporting UbiComp task, it should be easily executable without requiring a prolonged context switch as this greatly disrupts the primary task.

The user interface should reflect the simplicity and the potentially high cost of interaction. Having to interact with a screen, either hand-held or wall-mounted, in order to turn on the light would majorly disrupt people in reading their book, the primary task. Screen interaction requires full visual and cognitive attention; people would have to complete two context shifts for an interaction of negligible complexity. As a result, a device-, eyes-, and feedback-free interaction, such as a room-based interaction, would be preferable in this particular scenario.

Table 3: Comparison of UbiComp interaction scenarios

Input space Output / feedback space Cost of interruption

Movie selection Large Large None

Cooking recipe Medium Medium High

Switch on lights Small None High

These three scenarios clearly show that the requirements for interactions in smart environments can be so different that no single interaction technique will satisfy all of them: every technique has their individual strengths and weaknesses. While touch-based techniques will most likely keep their place in HEI, there are certain scenarios where people might prefer device-, system- feedback-, and eyes-free techniques. With room-based interaction, I present an interaction

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paradigm that covers some of the scenarios where touch-based techniques have some

shortcomings. In this sense, room-based interaction supplements existing techniques for HEI rather than replacing them.