Final answer:
The 'CONTRAST' statement in statistical analysis involves six groups and is used to compare the means of these groups using the specified contrast coefficients.
Step-by-step explanation:
The example statement appears to be related to a statistical software command for contrast analysis. In this command, 'CONTRAST 'label' grp 1 0 -1 1 -1 0 ;, the number of groups involved in the data can be inferred from the number of values following the 'grp' identifier. In this case, there are six groups represented by the numbers 1, 0, -1, 1, -1, and 0. This statement is intended to compare the means of these groups following the contrast coefficients provided. It specifies a particular set of comparisons among the levels of a factor variable, with contrast coefficients that are applied to the mean responses of these levels.