  There is a general agreement that it is important to consider the practical
relevance of an effect in addition to its statistical significance, yet a
formal definition of practical relevance is still pending and shall be provided
within this paper. It appears that an underlying decision problem,
characterized by actions and a loss function, is required to define the notion
of practical relevance, rendering it a decision theoretic concept. In the
context of hypothesis-based analyses, the notion of practical relevance relates
to specifying the hypotheses reasonably, such that the null hypothesis does not
contain only a single parameter null value, but also all parameter values that
are equivalent to the null value on a practical level. In that regard, the
definition of practical relevance is also extended into the context of
hypotheses. The formal elaborations on the notion of practical relevance within
this paper indicate that, typically, a specific decision problem is implicitly
assumed when dealing with the practical relevance of an effect or some results.
As a consequence, involving decision theoretic considerations into a
statistical analysis suggests itself by the mere nature of the notion of
practical relevance.
