Activar la intervención sobre la LCC

Searching as a specific form of browsing, is more weighted. While searching people are

asking “Is it here?”. Rapid serial visual presentation(RSVP) is a technique developed by

DE BRUIJN and SPENCE [dBS00] that displays electronic information, for instance, im-

ages from a folder, very fast one after another. The user can see every image only a brief moment and, thus, can quickly form a mental model of the folder’s content. This is particularly useful if a folder holds large amounts of images that cannot be displayed all at once.

(a) Carousel-mode. (b) Shelf-mode.

Figure 2.17:Dynamic RSVP techniques [Spe02].

There are different RSVP techiques. Static RSVP displays images at the same location.

Each image is only visible until it is replaced by the following image. In contrast, dy-

namic RSVP displays images in a stream. In that way an image can be visible even if other images are being displayed, as well. Static RSVP can be useful when the user is searching for a certain image, while dynamic RSVP can support browsing in a better way. People working in groups often have to deal with large amounts of information. Often everybody brings in own material and the other group members have to get an overview of this material before it is possible to start with the actual task. Dynamic RSVP tech- niques, such as carousel- or shelf-mode (see Figure 2.17), could be applied to interfaces on tabletop displays in order to support this functionality.

2.4 Chapter Summary

This chapter has given an overview of potential and problems of supporting co-located collaboration around large horizontal displays. First, the factors influencing collabora- tion between people in general were described followed by a short motivation for sup- porting collaboration by computers. After that, characteristics of tabletop displays were explained including possible technical settings, possible input devices, and interaction issues. The last section described a number of approaches of developing systems that support collaborative work in a certain way and ideas that have the potential of facilitat- ing co-located collaborative work. These systems and ideas were very inspiring for the

Chapter 2 Related Work

concept of Interface Currents, this thesis is about. The following chapter introduces the concept of Interface Currents together with the issues and research questions it raises and outlines an approach how these issues can be solved.

CHAPTER 3

Methodology

As described in Section 2.3, lazy Susans and conveyer belts in the real world support the sharing of items and information between multiple people. Similar to the PDH [SLV03]

and the Café Table [dBS01], the concept of Interface Currents developed by HINRICHSet

al. [HCS05a] is strongly motivated by these principles from the real world. It combines the principles of lazy Susans and conveyer belts flexibility and mobility to integrate the advantages of the physical techniques with the digital domain. Interface Currents, as a fluid and flexible interaction technique, offers the potential to help people share in- formation around a large horizontal display while supporting creativity during group collaboration. Subtle environmental orientation can be installed in certain areas of the workspace to ease the orientation problem. Furthermore, Interface Currents provide functionality for establishing public, personal, and storage territories and for transition- ing between parallel and collaborative work [HCS05a]. However, the potential benefits of how people will use Interface Currents have not been studied yet. In order to begin to understand the effectiveness of Interface Currents for supporting information sharing and creative activities during collaboration an observational user study was conducted. To provide sufficient background for this study this chapter begins by briefly explaining the concept, characteristics, and functionality of Interface Currents. Then the issues and research questions that arose from this concept are described, leading into an explana- tion of the study methodology used to expand the understanding of the purposes and roles Interface Currents can play in collaborative and creative tasks.

3.1 The Concept of Interface Currents

A current is a continuous onward movement traditionally thought of as existing in a body of liquid or gas. An Interface Current is defined as a mobile, flexible container that is dominated by an ongoing flow [HCS05a]. Digital information such as images or

Chapter 3 Methodology

documents can be placed on an Interface Current and are affected by the flow moving constantly similarly to leaves driven by a current in a river. An Interface Current is characterized by its directional flow, speed, confining boundaries, and its location.

3.1.1 Properties of Interface Currents

The fundamental properties of an Interface Current are theflow and the path in which

the flow travels. Depending on a Current’s location in the workspace its visibility can also be changed.

Flow

An Interface Current’s flow is defined by its direction and velocity. Both, direction and

velocity, are adjustable by the user independently. In the prototypes that HINRICHS et

al. [HCS05a] presented, the Interface Current’s flow is invisible unless information items are placed on it (see Figure 3.1(a) and 3.1(c)). Adding an item, however, causes it to follow the flow’s direction and velocity.

Path

An Interface Current flows in a path that has a location and some type of boundaries. The location of the path can either be fixed or mobile. The Current’s boundaries define its shape and size, indicating the areas that are affected by the flow. They can be rigid in that they are defined initially and not changed or they can be flexible and controlled by

either the user or the system. Apool-shapedCurrent is bordered by one single boundary

(see Figure 3.1(a)). It is comparable to a lake where the water flows in circles. The flow

(a) Pool-shaped Current. (b) Flow on a pool-

shaped Current. (c) Stream-shapedCurrent. (d) Flow on a stream-shaped Current.

Figure 3.1: Pool- and stream-shaped Interface Currents [HCS05a].

of a pool-shaped Current runs parallel to its boundary (see Figure 3.1(b)). A stream- shaped Current is confined by an inside and an outside boundary (see Figure 3.1(c)). Thus, items on a stream-shaped Current will flow like leaves on a river as mentioned above (see Figure 3.1(d)).

3.1 The Concept of Interface Currents

Visibility

While the path of an Interface Current defines its visual appearance, the location of the path determines its visibility. Depending on the purposes a Current is used for, its path can be totally visible, partly visible, or invisible (see Figure 3.2). If an Interface Current is used as a personal storage it can be reasonable to move it partly out of the workspace in order to save personal space (see Figure 3.2(c)). In contrast, Currents used in a group space for sharing items can be totally visible (see Figure 3.2(a) and 3.2(b)). Information items that are not currently needed can be moved out of the workspace by placing them on an Interface Current and moving this Current out of the workspace (see Figure 3.2(c)).

(a) Pool as a public territory. (b) Peripheral Current as a public

territory. (c) Partly visible and invisibleCurrents.

Figure 3.2:Visibility of Interface Currents and reorientation of items.

Interface Currents were developed to support fluid interaction during collaborative work. Possible purposes that Interface Currents could fulfill in a tabletop workspace are de- scribed in the following Section.

3.1.2 Possible Usage of Interface Currents

Interface Currents were not developed to fulfill one specific functionality. They were designed to support collaborative work, which can include several features. The follow- ing presents possible usages of Interface Currents that are imaginable when considering the findings from previous studies where tabletop collaboration was explored [SCI04, SGM03].

Chapter 3 Methodology

Providing a Group Space

An Interface Current can be used as a group space where information items can be shared among collaborating people. A large pool-shaped Current, for instance, placed in the middle of the workspace could be used as a virtual lazy Susan that is extended by reshaping and resizing functions (see Figure 3.2(a)). A stream-shaped Current sur- rounding the workspace could also be considered as a group space which helps people to share large amounts of information (see Figure 3.2(b)).

Providing Personal Storage Areas

Small Interface Currents can also be used as personal storage territories for storing per- sonal items. Large amounts of items can be stored on a partly visible Current in order to save personal workspace (see Figure 3.2(c)).

Facilitating Item Sharing

Items floating on an Interface Current always orient themselves towards the Current’s outer border (see Figures 3.2(a) and 3.2(b)). While information is floating, each group member can easily see information that passes in front of her. This approach of envi- ronmental orientation should ease the orientation problem on tabletop displays (see Sec- tion 2.2.4) and, furthermore, supports the sharing of information within a group. Items can be placed on an Interface Current that runs around the periphery of the tabletop workspace (see Figure 3.2(b)) in order to automatically pass them among group mem- bers. Pool-shaped Currents stretched out over a tabletop display can be used for sharing items, for instance, in order to work on the same task (see Figure 3.2(a)). At the same time, the flexibility of Interface Currents enables users to disconnect from collaborative work in order to work independently (see Figure 3.2(a) and 3.2(b)).

HINRICHSet al. [HCS05a] have described the concept and proposed possible implemen-

tation approaches for Interface Currents but how effective these Interface Currents are and what roles they can play during collaboration has not been formally studied. An exploratory user study was conducted to gain more insight in how people actually inter- act with Interface Currents, for what purposes they use them, and whether or not they would find them helpful. The questions and issues raised by the concept of Interface Currents are described in the following section.