RESEARCH METHOD COHEN ok

PROCEDURES IN EX POST FACTO RESEARCH 271
explanations for the empirical outcomes of the
study. A researcher has thus to beware of accepting
the first likely explanation of relationships in
an ex post facto study as necessarily the only
or final one. A well-known instance to which
reference has already been made is the presumed
relationship between cigarette smoking and lung
cancer. Health officials have been quick to seize on
the explanation that smoking causes lung cancer.
Tobacco firms, however, have put forward an
alternative hypothesis – that both smoking and
lung cancer are possibly the result of a third, as yet
unspecified, factor, i.e. the possibility that both the
independent and dependent variables are simply
two separate results of a single common cause
cannot be ignored.
Chapter 12