The Internet and the World Wide Web can bring a plethora of information to people on their computer desktops. Much of the information available electronically now is dynamic: stock prices fluctuate, news bulletins arrive, email queues grow, alarms sound and the weather changes. In this thesis, dynamic information refers to semi-structured data that changes or is updated at frequent intervals. While many people feel overwhelmed by information, it is still critical for them to know about the information that is important to them. For instance, people care when an important new software release occurs, when email arrives from their parents, when traffic is horrible on the interstate going home, when their file is caught behind five 20-megabyte jobs in the printer queue, and when a ball game is occurring that involves their favorite team. Clearly, the availability of this type of information can be good as long as it is desired information that is presented in an appropriate and non-intrusive manner.
With most information, especially static or infrequently-changing information, people seek to answer a question or make a decision. Consequently, they examine an interface, come to some conclusion, and move on. But with dynamic information, people's tasks more closely align to awareness, a process of maintaining knowledge about the state of and changes to a body of information. The desire to maintain awareness can occur on many levels that involve a wide range of priorities for information, bordered on one extreme by the monitoring of information for specific changes that will potentially change one's current actions and on the other extreme by a mild interest for information that will not affect one's current course of action.
As it is a new field, relatively few techniques have been explored for maintaining awareness of the contents of dynamic information sources. Current computer display tools generate innovative and complex visualizations, yet they can demand a person's full attention or can distract people from other daily tasks and as such are not well-suited for communicating information over a long period of time. While dynamic information is useful to a person throughout their daily activities, it often is complementary to other tasks such as entering data, editing a document, programming code, or writing. People want to maintain awareness of information, but they do not want this awareness to overwhelm their other work activities.
As such, it is advisable to communicate information in the periphery to allow people to focus on a primary task. While there are various means to integrate information in the environment, practical concerns motivated me to focus on alternatives suitable for the computer desktop. Since the majority of the screen space is dominated by tools necessary to support the primary task, peripheral displays must be fairly small. People use a variety of tools that fall into the category of peripheral displays, including clocks, load monitors, and email alert tools. Thus, it is reasonable to expect that people would be willing to use a peripheral tool for raising awareness of dynamic information.
Given that the information should be communicated in the periphery, what mechanisms can be used to facilitate it? One solution is the use of animation as a visual tool in maintaining awareness. What is animation? Baecker and Small describe it as ``sequences of static images changing rapidly enough to create the illusion of a continuously changing picture'' [3]. It has been used to generate emotion, provide entertainment, and supply information.
In general, animation refers to a visual change in an image or text, including changes in position, color, size, texture, or content. In this thesis, animation typically refers to constant and cyclic changes in information. When used in this way, animation can show a large amount of information in a small space in a hands-off manner. Tools such as stock tickers, sports wires, and banner advertisements use this type of animation to convey information, but such tools often have been criticized as being too distracting. It is my expectation that much of the distraction stems from the nature of the animations and the tasks for which they have been used. People may be willing to tolerate and even appreciate animation, but only if its benefits outweigh any potential drawbacks. I have been studying different types of animations to better understand their capabilities and utility for presenting dynamic information.
The focus of this work can be captured in the following thesis statement:
Constant and cyclic animations, when used in appropriate situations, can assist an individual in maintaining awareness of dynamic information.
This research contributes to the field of human-computer interaction by exploring the role of animation in maintaining awareness of dynamic information. In performing this research, I identified ways in which characteristics of peripheral displays can affect performance on both primary and peripheral tasks via empirical evaluations. I created a user interface toolkit that simplifies the inclusion of gradual, cyclic animated effects in peripheral awareness applications. I categorized users based on personal and situational qualities that then can be associated with animation preferences. In so doing, this thesis extends the understanding of the usefulness of peripheral animated displays.
The early stages of this thesis work were dedicated to exploring different ways to communicate information in the periphery. I built an information monitoring and display system that presented information using a variety of different communication mechanisms. A user study examined the ways in which people used the tool and analyzed which were the most effective. Chapter 3 describes this background work and explains how it led to the selection of animation as an awareness support technique for further study.
Having chosen to examine animated peripheral displays, the next step was to demonstrate their viability as a technique for helping users maintain awareness while completing other tasks. I designed a tool that presented information using a variety of types of animated displays and conducted a pilot study to survey if and how the tool would be used in a situation of fairly significant importance. Chapter 4 describes the pilot study and the lessons learned from it.
While the pilot study answered many questions, several new concerns were raised about the relative effectiveness and potential distraction of peripheral animated displays. To address these concerns, I conducted several empirical evaluations that studied the usefulness of animation in peripheral awareness displays. The evaluations examined qualities such as the type, size, and speed of the animated display. Chapter 5 provides details and results from these evaluations.
In building the tools and environments used in my evaluations, I noticed a lack of support in existing toolkits for the type of animation that proved to be useful in maintaining awareness. To address this need, I developed a toolkit that facilitates the programming of animated effects for awareness situations. Chapter 6 introduces this toolkit and outlines how it enables programmers to include animated effects into their programs quickly and easily.
The data from the empirical evaluations indicated that performance differences are related to characteristics of the animated display, but further research was needed to understand whether personal characteristics may also affect performance. I expanded the tool from the pilot study to include additional informational and display options and then conducted an observational study that asked in-depth questions and monitored users' interactions to gain a deeper understanding of how users are similar and how they differ. The study resulted in a set of user profiles that could be used to predict animation preferences. Chapter 7 gives details about the observational study.
Finally, Chapter 8 provides some conclusions, describes potential future work, and outlines the contributions of this thesis.