chi-square_test

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 chi-square_test [2016/05/16 08:21]hkimscil chi-square_test [2016/05/16 08:21] (current)hkimscil Both sides previous revision Previous revision 2016/05/16 08:21 hkimscil 2016/05/16 08:21 hkimscil 2016/05/16 08:20 hkimscil 2016/05/16 08:15 hkimscil 2016/05/16 08:13 hkimscil 2016/05/16 08:12 hkimscil 2016/05/16 08:08 hkimscil 2016/05/16 07:52 hkimscil 2016/05/16 07:51 hkimscil 2016/05/16 07:50 hkimscil 2016/05/16 07:49 hkimscil 2016/05/16 07:49 hkimscil 2016/05/16 07:47 hkimscil 2016/05/16 07:45 hkimscil 2016/05/16 07:41 hkimscil 2016/05/16 07:39 hkimscil 2016/05/16 07:36 hkimscil 2016/05/16 07:32 hkimscil 2016/05/16 07:31 hkimscil 2016/05/16 07:27 hkimscil 2016/05/16 07:27 hkimscil created 2016/05/16 08:21 hkimscil 2016/05/16 08:21 hkimscil 2016/05/16 08:20 hkimscil 2016/05/16 08:15 hkimscil 2016/05/16 08:13 hkimscil 2016/05/16 08:12 hkimscil 2016/05/16 08:08 hkimscil 2016/05/16 07:52 hkimscil 2016/05/16 07:51 hkimscil 2016/05/16 07:50 hkimscil 2016/05/16 07:49 hkimscil 2016/05/16 07:49 hkimscil 2016/05/16 07:47 hkimscil 2016/05/16 07:45 hkimscil 2016/05/16 07:41 hkimscil 2016/05/16 07:39 hkimscil 2016/05/16 07:36 hkimscil 2016/05/16 07:32 hkimscil 2016/05/16 07:31 hkimscil 2016/05/16 07:27 hkimscil 2016/05/16 07:27 hkimscil created Line 175: Line 175: I do not know exactly why the degree of freedom is important in a conceptual way -- so, having a difficulty explaining it. But, the idea behind it is that if you know totals of column and row, and the values of two cells (as a minimum requirement;​ called degree of freedom), you would be able to obtain the values of the other four cells without consulting the actual observed values. I do not know exactly why the degree of freedom is important in a conceptual way -- so, having a difficulty explaining it. But, the idea behind it is that if you know totals of column and row, and the values of two cells (as a minimum requirement;​ called degree of freedom), you would be able to obtain the values of the other four cells without consulting the actual observed values. - {{07-419434-a-tshirt-camp-scils-rutgers.jpg?​202 |RUSURE campaign SCILS Rutgers 2000}} Anyway, you just obtained the chi-square value (37.58) and the degrees of freedom (2). You can look up the text book (for chi-square test): (1) find your degrees of freedom (2), that is, the second row of the table; (2) decide the probability you want to employ (usually .05 or .01); (3) write down the numbers; and (4) compare them to your chi-square value. (see [[:chi square distribution table]]) + {{07-419434-a-tshirt-camp-scils-rutgers.jpg?​202 |RUSURE campaign SCILS Rutgers 2000}} Anyway, you just obtained the chi-square value (37.58) and the degrees of freedom (2). You can look up the text book (for chi-square test): (1) find your degrees of freedom (2), that is, the second row of the table; (2) decide the probability you want to employ (usually .05 or .01); (3) write down the numbers; and (4) compare them to your chi-square value. (see [[:chi-square distribution table]]) The numbers you obtain from the book are 5.991 for the 0.05 probability and 9.210 for the 0.01 probability. They are called critical values. So the critical values are: The numbers you obtain from the book are 5.991 for the 0.05 probability and 9.210 for the 0.01 probability. They are called critical values. So the critical values are: Line 265: Line 265: __Another note:__ You might have a question... Hey, wait a minute... If I pick up some other numbers from the chi-square distribution table, the result would be totally different! ​ __Another note:__ You might have a question... Hey, wait a minute... If I pick up some other numbers from the chi-square distribution table, the result would be totally different! ​ - For your information,​ the table looks as follows. And the chi-square value you got from your data was 2.73 (see [[:Chi square distribution table]]). + For your information,​ the table looks as follows. And the chi-square value you got from your data was 2.73 (see [[:Chi-square distribution table]]). | df  | .30  | .20  | .10  | .05  | .02  | .01  | .001  | | df  | .30  | .20  | .10  | .05  | .02  | .01  | .001  | | 1  | 1.074  | 1.642  | 2.706  | 3.841  | 5.412  | 6.635  | 10.827 ​ | | 1  | 1.074  | 1.642  | 2.706  | 3.841  | 5.412  | 6.635  | 10.827 ​ |