An increasing number of tasks require that users coordinate and operate on information from multiple sources. Each source of information is typically contained within a window, the fundamental unit at which users currently manipulate information. With continuing advances in computing and networking capabilities, users can open large numbers of windows, each containing different information. Often, users benefit from simultaneously viewing related information that exists within different windows. Additionally, the spatial layout of this information may be crucial to effective task performance as it helps users not only to establish spatial relationships but also to visually compare contents.
Subsequent chapters in this book describe various projects aimed at making users more efficient at managing and performing their tasks. Due to the various interpretations of what constitutes a coherent activity, each project defines the meaning of a task differently. We have found, through interviews, that many end-users loosely define a task by a group of windows and the actions that operate on them. Examples include working on finances, writing a paper, or managing correspondence, each of which may involve a continuously changing set of many different windows and/or applications. Users today are faced with an increasingly difficult job of managing these windows and tasks. In this chapter we describe our work in building tools that allow users to effectively manipulate windows on their desktop in order to complete their tas