  Ockham's razor is a heuristic concept applied in philosophy of science to
decide between two or more feasible physical theories. Ockham's razor operates
by deciding in favour of the theory with least assumptions and concepts;
roughly speaking, the less complex theory. Could Ockham's razor not easily
treat the different interpretations as theories and decide in favour of the one
with fewest assumptions? We provide an answer to this question by means of
examples of applications in literature and the discussion of its historical
origin. We review the historical context of Ockham's razor and its connection
to medieval philosophical struggles, discuss the essence of its parsimonious
core and put it in relation with modern struggles in the context of
interpretational issues in Quantum Mechanics. Due to the lack of experimental
evidences in string theory, a new field of modern heuristics arose in the last
years. We will discuss these heuristics in the context of Ockham-related
heuristic methods and analyse the connection of these heuristics with the
interpretations of Quantum Mechanics.
