chi squared test

• what is chi squared used for?

  identifying patterns in data, highlighting differences that exist or to identify relationships within sets of results
• what are the advantages of chi squared?

  the test is useful in measuring the differences between what is observed and expected

  it is useful when the expected distribution of the data is not known

  it is useful when data can be grouped into classes

  the x2 value can be compared with significant tables to determine whether any deviation from random in the observed data is a chance effect or if it possesses statistical significance
• what are the limitations of using chi squared?

  data must be in the form of frequencies

  data must have precise numerical values and be organised into categories or groups

  the expected frequency in any one cell must be greater than five