Items within your scope?
In reading what you've written so far, am I correct in that you are focusing on relatively long-term information results in classical expertise, or are things that are more tactical or real-time within scope? When I speak of "tactical", I'm thinking about span of control of a manager or commander. For example, in the Incident Command System, which is the North American and increasingly worldwide paradigm for emergency response — it came out of firefighting — there is a strong emphasis on not having more than five direct reports, and perhaps 2-3 staff assistants. Similar span of control guidelines exist in military combat operations, and are becoming exceptionally complex as there are increasing requirements to track peers as well as subordinates.
With respect to real-time, I'm thinking of situational awareness, which could be manifested in the number of significant displays, or views, of a situation that an individual can use concurrently and productively. For example, in microsurgery, where there are multiple views available, clinicians appear to concentrate on one or two displays, but will want approximately five available as secondary sources. New combat aircraft have tended to have four main displays, perhaps in addition to a heads-up display. One new aircraft is putting electro-optical sensors on each axis of an aircraft, so the pilot theoretically has no blind spots. Can, however, a pilot stay aware of six external views plus instrumentation? Howard C. Berkowitz 20:18, 23 July 2008 (CDT)
According to this article, "Alvin Toffler coined the phrase “information overload” in 1970" in "Toffler A. Future shock. Bodley Head, 1970", which I haven't found online other than as metadata. There are a few earlier usage examples, though. --Daniel Mietchen 00:31, 2 February 2011 (UTC)