Mind, Body, World- Foundations of Cognitive Science, 2013a

2
Multiple Levels of Investigation
2.0 Chapter Overview
Cognitive science is an intrinsically interdisciplinary field of study. Why is this so?
In the current chapter, I argue that the interdisciplinary nature of cognitive science
necessarily emerges because it assumes that cognition is information processing.
The position I take is that explanations of information processors require working
at four different levels of investigation, with each level involving a different vocabulary
and being founded upon the methodologies of different disciplines.
The chapter begins with a historical treatment of logicism, the view that thinking
is equivalent to performing mental logic, and shows how this view was converted
into the logical analysis of relay circuits by Claude Shannon. Shannon’s work is then
used to show that a variety of different arrangements of switches in a circuit can
perform the same function, and that the same logical abilities can be constructed
from different sets of core logical properties. Furthermore, any one of these sets of
logical primitives can be brought to life in a variety of different physical realizations.
The consequence of this analysis is that information processors must be
explained at four different levels of investigation. At the computational level, one
asks what kinds of information processing problems can be solved by a system. At
the algorithmic level, one asks what procedures are being used by a system to solve a
particular problem of interest. At the architectural level, one asks what basic operations
are used as the foundation for a specific algorithm. At the implementational
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