hypothesis test make assumptions
about the underlying distribution of the
population from which the sample is being
drawn, and which is being investigated.
This is typically that the population conforms
to a normal distribution.
Parametric hypothesis tests include:
||comparing the means of several (more
than two) samples
||testing 'goodness of fit' to
an assumed distribution
||a variation on the chi-square test
||for differences between large or small
||comparing the mean to a value, or
the means of two samples
||as t-test but for large samples
If the underlying distribution of the population
is not known then a nonparametric
test would be used. This would
not be as powerful because it cannot use
the predictable properties of the distribution.