Testing Normality

[knargis160]

Hi!

I want to test the normality of data within a group rather than comparing groups-what is difference in class and by statements.

Can we use where statement to test normality within one group?

proc univariate data= mon6 normaltest;
var cohesion;
histogram / normal;
qqplot cohesion/normal(mu=est sigma =est) square;
class condition;
run;

[Reeza]

If you use BY statements each group is treated independently it’s just repeated for each BY group.
CLASS is similar but doesn’t require the data to be presorted and will also do subgroups at the same time, if you have multiple variables defining your BY groups.

Yes, you can also use WHERE to filter your data set to a single group at a time. The results of the test is the same regardless of approach.