# Descriptive Statistics by Groups (Breakdown) Introductory Overview - Arrangement of Data

In the following example data set (spreadsheet), the dependent variable WCC (White Cell Count) can be broken down by 2 independent variables: Gender (values: males and females), and Height (values: tall and short):

 GENDER HEIGHT WCC case 1 male short 101 case 2 male tall 110 case 3 male tall 92 case 4 female tall 112 case 5 female short 95 ... ... ... ...

The resulting breakdowns might look as follows (we are assuming Gender was specified as the first independent variable, and Height as the second):

 Entire sample Mean=100 SD=13 N=120 Males Mean=99 SD=13 N=60 Females Mean=101 SD=13 N=60 Tall/males Mean=98 SD=13 N=30 Short/males Mean=100 SD=13 N=30 Tall/females Mean=101 SD=13 N=30 Short/females Mean=101 SD=13 N=30

The composition of the "intermediate" level cells of the "breakdown tree" depends on the order in which independent variables are arranged. For example, in the above example, you see the means for "all males" and "all females" but you do not see the means for "all tall subjects" and "all short subjects," which would have been produced had you specified independent variable Height as the first grouping variable rather than the second. Thus, ideally, in a breakdown program you should have an option to easily "reorder" independent variables and thus see different "cross-sections" of the data. The Basic Statistics and Tables module gives you not only the option to reorder the variables in the table, but it also allows you to compute any marginal table in which you may be interested. For example, you could easily compute the means for Tall and Short individuals.