WEBVTT 00:00:00.000 --> 00:00:01.494 align:middle line:90% [MUSIC PLAYING] 00:00:01.494 --> 00:00:15.960 align:middle line:90% 00:00:15.960 --> 00:00:17.970 align:middle line:84% Hello and welcome to a quick tutorial 00:00:17.970 --> 00:00:22.020 align:middle line:84% on how to calculate a chi-square using PSPP. 00:00:22.020 --> 00:00:25.350 align:middle line:84% Now, we are using the chi-square.sav data set. 00:00:25.350 --> 00:00:26.850 align:middle line:84% This is the data set that goes along 00:00:26.850 --> 00:00:30.146 align:middle line:84% with the example in the chi-square chapter. 00:00:30.146 --> 00:00:31.770 align:middle line:84% If you remember, it's basically looking 00:00:31.770 --> 00:00:34.600 align:middle line:84% at the differences between females and males 00:00:34.600 --> 00:00:37.860 align:middle line:84% and when they took public speaking in college. 00:00:37.860 --> 00:00:41.670 align:middle line:84% So you'll see over here we have two different variables. 00:00:41.670 --> 00:00:44.187 align:middle line:84% We had Sex and we had Class, which is again 00:00:44.187 --> 00:00:46.020 align:middle line:84% what classification they were-- whether they 00:00:46.020 --> 00:00:47.890 align:middle line:84% were a first-year student, sophomores, juniors, 00:00:47.890 --> 00:00:48.390 align:middle line:90% or seniors. 00:00:48.390 --> 00:00:50.770 align:middle line:84% And Sex, of course, was males and females. 00:00:50.770 --> 00:00:53.070 align:middle line:84% So to analyze and conduct a chi-square, 00:00:53.070 --> 00:00:58.070 align:middle line:84% you go to Analyze, Descriptive Statistics, Crosstabs. 00:00:58.070 --> 00:01:00.960 align:middle line:84% And then the Crosstabs menu is going to pop up. 00:01:00.960 --> 00:01:03.480 align:middle line:84% Now, what you want to do is select your first variable, 00:01:03.480 --> 00:01:06.240 align:middle line:84% in this case Sex, and click the arrow next to the Rows box. 00:01:06.240 --> 00:01:09.570 align:middle line:84% And then Class, and select the arrow next to the Columns box. 00:01:09.570 --> 00:01:12.420 align:middle line:84% That's going to put your two nominal variables over 00:01:12.420 --> 00:01:14.380 align:middle line:84% into the boxes where they need to be. 00:01:14.380 --> 00:01:17.110 align:middle line:84% And then all you have to do is click on the Statistics button. 00:01:17.110 --> 00:01:20.400 align:middle line:84% You'll notice that Chi-Square is automatically selected for us. 00:01:20.400 --> 00:01:22.950 align:middle line:84% We want to go ahead and also select that Phi. 00:01:22.950 --> 00:01:24.570 align:middle line:90% This is Cramer's Phi. 00:01:24.570 --> 00:01:27.120 align:middle line:84% So we're going to then go ahead and click Continue on that. 00:01:27.120 --> 00:01:30.640 align:middle line:84% And at that point, all you have to do is click OK. 00:01:30.640 --> 00:01:33.430 align:middle line:84% And here is what the results are going to look like. 00:01:33.430 --> 00:01:35.160 align:middle line:84% The first big box here is just letting 00:01:35.160 --> 00:01:36.990 align:middle line:84% you know the number of people that we had. 00:01:36.990 --> 00:01:39.150 align:middle line:84% In this case it was 100, so that's 00:01:39.150 --> 00:01:40.770 align:middle line:90% what you're going to see there. 00:01:40.770 --> 00:01:42.570 align:middle line:84% Then we have the breakdown table, 00:01:42.570 --> 00:01:45.139 align:middle line:84% so you know how many males took it 00:01:45.139 --> 00:01:47.430 align:middle line:84% when they were in pre-college, how many females took it 00:01:47.430 --> 00:01:49.650 align:middle line:90% when they were seniors. 00:01:49.650 --> 00:01:52.470 align:middle line:84% So that you have the, again, percentages and the percentages 00:01:52.470 --> 00:01:53.205 align:middle line:90% of the totals. 00:01:53.205 --> 00:01:55.830 align:middle line:84% Which is why you can always have the count, row percent, column 00:01:55.830 --> 00:01:57.970 align:middle line:90% percent, and the total percent. 00:01:57.970 --> 00:02:01.020 align:middle line:84% So in this case, the count was 6. 00:02:01.020 --> 00:02:04.020 align:middle line:84% The row percent was 12, so that's 12% of males. 00:02:04.020 --> 00:02:06.570 align:middle line:84% The column percent basically lets 00:02:06.570 --> 00:02:09.690 align:middle line:84% us know that it accounted for 46.5% of those 00:02:09.690 --> 00:02:11.009 align:middle line:90% who took it in pre-college. 00:02:11.009 --> 00:02:12.670 align:middle line:90% And 6% of the actual total. 00:02:12.670 --> 00:02:16.039 align:middle line:84% So that's what those extra numbers there are telling us. 00:02:16.039 --> 00:02:18.330 align:middle line:84% From there you actually have your chi-square statistic. 00:02:18.330 --> 00:02:19.170 align:middle line:90% It's right here. 00:02:19.170 --> 00:02:21.050 align:middle line:84% It's the one that says Pearson Chi-Square. 00:02:21.050 --> 00:02:23.580 align:middle line:90% The value was 22.36. 00:02:23.580 --> 00:02:26.250 align:middle line:90% The degrees of freedom was 4. 00:02:26.250 --> 00:02:31.290 align:middle line:84% And the significance level of the p-value was 0.000. 00:02:31.290 --> 00:02:36.420 align:middle line:84% Don't forget, in APA style, we always report it only at p 00:02:36.420 --> 00:02:38.580 align:middle line:90% is less than 0.001. 00:02:38.580 --> 00:02:44.520 align:middle line:84% So 0.000 would be turned into p is less than 0.001. 00:02:44.520 --> 00:02:48.609 align:middle line:84% And last but not least, we have both Phi and Cramer's V here. 00:02:48.609 --> 00:02:50.400 align:middle line:84% You'll notice those are those same numbers, 00:02:50.400 --> 00:02:54.530 align:middle line:84% so we just usually report Cramer's Phi of 0.47, 00:02:54.530 --> 00:02:57.030 align:middle line:84% letting us know the magnitude of this difference. 00:02:57.030 --> 00:03:01.440 align:middle line:84% And that is how you can run a chi-square using PSPP. 00:03:01.440 --> 00:03:03.590 align:middle line:90% [MUSIC PLAYING] 00:03:03.590 --> 00:03:15.580 align:middle line:90%