Interactive delayed-sharing of computer-supported workspaces via the streaming of re-executable content.

Abstract

This dissertation introduces the notion of interactive delayed-sharing of a session on a computer-supported workspace to allow reuse of such session at a later time. A data artifact, referred to as a session object, encapsulates the session. A session object is composed of heterogeneous multimedia streams that represent temporally-ordered input sequences to applets in the workspace. Playback of a session object recreates the underlying workspace spanned by these applets through the streaming and re-execution of these input sequences in their respective applets. The contributions of this dissertation are as follows. First, this dissertation pioneers the re-execution approach to the record and replay of sessions for supporting computer-supported collaborative work. In doing so, it introduces a novel paradigm for flexible support of asynchronous collaboration that allow users to collaborate by annotating, editing, and refining these delayed-shared workspaces. This dissertation explores these collaborative features particularly focusing on the record, representation, and playback of these workspaces. Second, this dissertation introduces the notion of workspaces as authored, transportable, and temporally-aware artifacts and investigates flexible mechanisms for the delivery of temporal-awareness to workspaces composed of heterogeneous applications through the decoupling of tool and media services. This dissertation develops a formal specification through temporal relationships in these workspaces. Finally, this dissertation describes mechanisms for the integration of re-executable content streams together with continuous multimedia streams. It describes a framework for media-independent integration of these heterogeneous streams and their temporal constraints. The dissertation introduces the use of statistical process controls to guide the relaxation and/or constraint of scheduling and synchronization mechanisms so as to flexibly support a range of heterogeneous media streams and their temporal relationships.