topic Re: Chi-square test for each row in SAS Procedures

Chi-square test for each row

Marjolein — Fri, 21 Oct 2016 13:29:04 GMT

Hi all,

I'm interested in knowing whether the individual levels of my row variable are related to my column variable in a contingency table.

Is SAS able to produce Chi-square tests for each row of your contingency table, in stead of a general chi-square test? I cannot seem to work out how to do it.

Thanks in advance!

Re: Chi-square test for each row

ballardw — Fri, 21 Oct 2016 14:33:44 GMT

You should provide a brief example of your data (variable names help the discussion) and the say which are needed for your test. Since chi-sq also wants count values you will need to indicate which are the category values and which are the counts for those values.

Often data needs to be reshaped before some tests.

Re: Chi-square test for each row

Ksharp — Sat, 22 Oct 2016 03:27:09 GMT

You mean One-Way Chi-square ?

proc freq data=sashelp.class;
where age=14;
table sex/ testp=(0.5 0.5); *testf=(10 6);
run;

Re: Chi-square test for each row

Marjolein — Mon, 24 Oct 2016 07:33:39 GMT

OK, I understand! 🙂

For example: I have my row variable SES, with the levels low, moderate and high. I want to test, whether each level of SES is associated with physical activity which has been divided in four categories (no, moderate, active, severe). What I want to get out is 3 p-values, each indicating whether the level of SES (low, moderate and high) is associated with the level of physical activity.

I know that Chi-square generally tells you whether the two variables are associated, but can you also ask for row-specific tests?

Am I making myself more clear now? 🙂 I hope so. Please let me know if not.

Re: Chi-square test for each row

Marjolein — Mon, 24 Oct 2016 07:37:54 GMT

Not quite, see my more clear explanation above: I have two categorical variables, but I don't want to know whether they are related in general, but I want to see whether each level of my row variable (SES: low, moderate, high) is associated with my column variable (physical acitivy: four levels). So I want three P-values: each indicating whether the level of SES is associated with physical acitivity.

Re: Chi-square test for each row

Ksharp — Mon, 24 Oct 2016 10:42:13 GMT

If you want test " each level of SES" , that mean these three row level is independent. That make "association" nonsense.

if column level from first to last , what gonna do with the single row level ? You can ONLY measure "association" between two variables which have more than two levels .

You can try Trend Analysis ,but that is only for 2xn or nx2 contingency table.

Example 40.8: Cochran-Armitage Trend Test

Re: Chi-square test for each row

Marjolein — Mon, 24 Oct 2016 10:50:43 GMT

OK I see, thank you!