Question: 如何进行分类对比, 或者是按某一数据的上下25%进行对总体 数据进行分类对比
MEANS AS SUMMARIES OF DISTRIBUTIONS
It is often useful to examine means or averages of a variable according to categories of other variables, such as education. When we do this, we should have some statistical model or hypothesis in mind.
In this example, using the data set IMMUNR.SAV, we wish to confirm the expected result that on average older children will have older mothers than younger children. We do this by examining whether the mean age of mothers will be older for older children than for younger children. The variable for which the mean is calculated must be an interval variable (or possibly a dichotomous variable with values of 0 and 1) if the calculation is to be meaningful.
Exercise E.1
Open the data set IMMUNR.SAV. Request the mean age of mothers for each age category of youngest child:
MEANS TABLES=AGE BY AGECYC.
The output looks like the following display.
You can see that the mean age of the mothers of the youngest category of children is 26.5 years, while the mean age of mothers for the oldest children is 36.2 years. This agrees with our expectation.
We also know that as education for women has increased rapidly in Indonesia in the past 20 or so years, so older women, on average, are less educated than younger women. This should mean that the average age of less educated women is expected to be higher than the average age of more educated women.
Exercise E.2
Calculate means for age of mother according to education of the mother:
MEANS TABLES=AGE BY EDUCR.