Abstract-In the domain of intelligent systems the management of system resources is typically called "attention". Attention mechanisms exist because even environments of moderate complexity are a source of vastly more information than available cognitive resources of any known intelligence can handle. Cognitive resource management has not been of much concern in artificial intelligence (AI) work that builds relatively simple systems for particular targeted problems. For systems capable of a wide range of actions in complex environments, explicit management of time and cognitive resources is not only useful, it is a necessity. We have designed a general attention mechanism for intelligent systems. While a full implementation remains to be realized, the architectural principles on which our work rests have already been implemented. Here we examine some prior work that we find relevant to engineered systems, describe our design, and how it derives from constructivist AI principles.