  Hugh Everett III presented pure wave mechanics, sometimes referred to as the
many-worlds interpretation, as a solution to the quantum measurement problem.
While pure wave mechanics is an objectively deterministic physical theory with
no probabilities, Everett sought to show how the theory might be understood as
making the standard quantum statistical predictions as appearances to observers
who were themselves described by the theory. We will consider his argument and
how it depends on a particular notion of branch typicality. We will also
consider responses to Everett and the relationship between typicality and
probability. The suggestion will be that pure wave mechanics requires a number
of significant auxiliary assumptions in order to make anything like the
standard quantum predictions.
