 
Summary: Application of quantum statistics in psychological
studies of decision processes
Diederik Aerts and Sven Aerts
Center Leo Apostel (CLEA)
Brussels Free University
Pleinlaan 2, 1050 Brussels, Belgium
diraerts@vub.ac.be, saerts@vub.ac.be
Abstract
We present a new approach to the old problem of how to incorporate the
role of the observer in statistics. We show classical probability theory to
be inadequate for this task and take refuge in the epsilonmodel, which
is the only model known to us capable of handling situations between
quantum and classical statistics. An example is worked out and some
problems are discussed as to the new viewpoint that emanates from our
approach.
1 Introduction
The quantum probability theory is fundamentally different from the classical
probability theory. The core of the difference lies in the fact that in quantum
probability we are dealing with the actualization of a certain property during the
measurement process, while in classical probability all properties are assumed
