"How a Cockpit Remembers Its Speeds". Edwin Hutchins applies cognitive science to a unit of analysis that is larger than one person. A pilot and ethnographer of [flight decks], Hutchins paper is a fascinating deep-dive into an essential moment in the complex socio-technical system of commercial aviation. pdf 
Without a speed bug, on final approach the pilot flying must remember the approach speed, read the airspeed indicator scale to find the remembered value of the approach speed on the airspeed indicator scale, and compare the position of the ASI needle on the scale with the position of the approach speed on the scale. With the salmon bug set, the pilot no longer needs to read the airspeed indicator scale. He or she simply looks to see whether or not the indicator needle is lined up with the salmon bug. Thus, a memory and scale reading task is transformed into a judgment of spatial adjacency.
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Twice in this example, a change in the nature of the representation of information results in a change in the nature of the cognitive task facing the pilot. In the first case, the speed bug itself permits a simple judgement of spatial proximity to be substituted for a scale reading task operation. In the second case, the pilot not flying further transforms the task facing the pilot flying from a judgment of spatial proximity (requiring scare visual resources) into a task of monitoring a particular aural cue (a phrase like, "five knots fast"). Notice also that the change in the task for the pilot flying changes the kinds of internal knowledge structures that must be brought into play in order to decide on appropriate action.
# The Pilot's Memory for Speeds
Memory is normally thought of as a psychological function internal to the individual. However, memory tasks in the [flight deck] may be accomplished by functional systems which transcend the boundaries of the individual actor. Memory processes may be distributed among human agents, or between human agents and external representational devices.
In some sense, the speeds are being remembered by the crew, partly, I suspect, in the usual sense of individual internal memory. But the speeds are also being read, written, and compared to other speeds in many representations. They are being compared to long-term memories for the typical or expected speeds for a plane of this specific weight. The comparison might be in terms of numbers; that is "Is 225 KIAS a fast or a slow speed for initial flap extension?" The comparison could also take place in terms of the number in the pilot's head, or on the landing data card, or on the position of the first bug in the airspeed indicator, or all of these together.
... The memory observed in the [flight deck] is a continual interaction with a world of meaningful structure. The pilots continually are reading and writing, reconstituting and reconstructing the meaning and the organization of both the internal and the external representations of the speeds. It is not just the retrieval of something from an internal store-house, and not just a recognition or a match of an external form to an internally stored template. It is, rather, a combination of recognition, recall, pattern matching, cross modality consistency checking, construction, and reconstruction that is conducted in interaction with a rich set of representational structures, many of which permit, but do not demand, the reconstruction of some internal representation that we would normally call the "memory" for the speed.
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The whole paper is fascinating.
I'm struck by how much better the information architecture of a 1995 flight deck is with fairly low-tech parts (a table of numbers, a specialized deck of cards, a speedometer, movable tics around its edge, and procedural communication between pilots) compared to modern software operations.
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As a slow reader I had trouble finishing the paper. Your excerpts have been quite handy.
I am reminded of a report where the author was quite skeptical of the maintenance habits of a third-world airline when he notice that instruments were ajar until he saw that once at cruise all indicators pointed straight up.
Stigmergy, most often cited in connection with ants, is a mechanism of indirect coordination, through the environment, between agents or actions. wikipedia
Refactoring of source code or even wiki pages can be thought of as a form of Stigmergy. What I missed from the paper until I read your summary is how the cognitive task of interpreting the memory differs with each alternative.
See Edit Music for an application that visualizes and sonifies the wikipedia edit stream.