This is a chi-square calculator for goodness of fit (for alternative chi-square
calculators, see the column to your right).
The chi-square test for goodness of fit tests whether an observed frequency distribution
of a nominal variable matches an expected frequency distribution. For example, suppose
a group of patients has been undergoing an experimental treatment, and then have
their health assessed to see whether their condition has improved, stayed the same
or worsened. A goodness of fit test could be used to determine whether the numbers
in each category - improved, no change, worsened - match the numbers that would
be expected given the standard treatment option.
The first stage is to enter category information into the text boxes below (this calculator
allows up to five categories - or levels - but fewer is fine). So, for example,
if you were looking at whether an experimental medical treatment is effective, you
might have the categories Improved, No Change, Worsened (entered into the top three
boxes below). Once you've added your category information, press Next.