WEBVTT Kind: captions; language: en-us NOTE Treffsikkerhet: 81% (H?Y) 00:00:00.000 --> 00:00:09.800 In this video I will show you how to compute Z scores in Jimovie. Let us load our data set. NOTE Treffsikkerhet: 91% (H?Y) 00:00:12.600 --> 00:00:22.600 Let's say that you want to compute the Z scores for the first variable here, matrices at kindergarten. NOTE Treffsikkerhet: 91% (H?Y) 00:00:25.200 --> 00:00:29.100 So we click on this variable NOTE Treffsikkerhet: 91% (H?Y) 00:00:29.100 --> 00:00:32.000 and then we go to data, NOTE Treffsikkerhet: 91% (H?Y) 00:00:32.000 --> 00:00:34.500 compute, NOTE Treffsikkerhet: 85% (H?Y) 00:00:35.500 --> 00:00:41.400 and we are presented with the new variable here NOTE Treffsikkerhet: 90% (H?Y) 00:00:41.700 --> 00:00:49.500 which is initially named with some letter of the alphabet, and we have to give our own name, so let's 00:00:49.500 --> 00:00:51.550 say this will be z NOTE Treffsikkerhet: 91% (H?Y) 00:00:51.550 --> 00:00:53.850 matrices. NOTE Treffsikkerhet: 68% (MEDIUM) 00:00:53.850 --> 00:00:56.400 0k. NOTE Treffsikkerhet: 88% (H?Y) 00:00:56.400 --> 00:01:03.700 And we can add a description if we aren't sure and want to remember Z score. NOTE Treffsikkerhet: 91% (H?Y) 00:01:04.400 --> 00:01:10.400 This is completely optional we don't have to add a description here. NOTE Treffsikkerhet: 89% (H?Y) 00:01:14.600 --> 00:01:23.700 So to compute the Z scores we have to enter a formula here, a formula is a set of instructions of 00:01:23.700 --> 00:01:31.200 what numbers to use and what to do with them. So what we want to do is to use the functions 00:01:31.200 --> 00:01:38.900 that are provided by Jimovie. I will show you the direct way first so if I click on functions, NOTE Treffsikkerhet: 91% (H?Y) 00:01:38.900 --> 00:01:41.600 and you go down NOTE Treffsikkerhet: 87% (H?Y) 00:01:42.000 --> 00:01:45.949 you will see that there is a z function here. NOTE Treffsikkerhet: 91% (H?Y) 00:01:45.949 --> 00:01:49.100 You can double-click on it, NOTE Treffsikkerhet: 91% (H?Y) 00:01:49.300 --> 00:01:58.200 and so it appears up there and the cursor is now inside the parentheses. NOTE Treffsikkerhet: 87% (H?Y) 00:01:58.200 --> 00:02:02.850 So we go on to the variables column, NOTE Treffsikkerhet: 91% (H?Y) 00:02:02.850 --> 00:02:12.800 find the variable we are interested in which is this one, double click on it and it is copied up there. So 00:02:12.800 --> 00:02:21.500 we took this from here, and this from here, then this is the expression that we have created. And we're 00:02:21.500 --> 00:02:23.600 done this is it. NOTE Treffsikkerhet: 86% (H?Y) 00:02:23.600 --> 00:02:29.000 So we can click outside and these are our Z scores. NOTE Treffsikkerhet: 89% (H?Y) 00:02:29.300 --> 00:02:37.200 We didn't have to select them from down here, we could just as well, I'm going to delete this now by 00:02:37.200 --> 00:02:47.900 pressing backspace, and type Z parentheses matrices 0, K capital K NOTE Treffsikkerhet: 78% (H?Y) 00:02:47.900 --> 00:02:55.600 close parenthesis, enter and that's exactly the same thing. Though the list helps when you don't 00:02:55.600 --> 00:03:02.100 remember the names and also helps to make sure you type the variable name exactly, because if you 00:03:02.100 --> 00:03:10.700 don't type it exactly then you will get an error say type 1 instead of 0, and I get an error message 00:03:10.700 --> 00:03:18.000 so an error message means I mistyped something I have to find out what it is and do it correctly. NOTE Treffsikkerhet: 77% (H?Y) 00:03:19.800 --> 00:03:25.300 Let's now practice with a different way to derive the same thing. NOTE Treffsikkerhet: 88% (H?Y) 00:03:25.900 --> 00:03:33.300 Let's click on the original variable and click on compute again, NOTE Treffsikkerhet: 78% (H?Y) 00:03:34.800 --> 00:03:39.100 and I'm going to name this variable NOTE Treffsikkerhet: 91% (H?Y) 00:03:40.500 --> 00:03:46.649 something different so that it stands out in the variable list, NOTE Treffsikkerhet: 87% (H?Y) 00:03:46.649 --> 00:03:51.900 and instead of using the Z function I'm going to go around NOTE Treffsikkerhet: 91% (H?Y) 00:03:52.200 --> 00:03:55.200 and use the formula NOTE Treffsikkerhet: 86% (H?Y) 00:03:55.200 --> 00:04:04.500 so what is the formula for getting a z-score ? Well I need each value, I'm going to double click on the 00:04:04.500 --> 00:04:06.250 original variable, NOTE Treffsikkerhet: 91% (H?Y) 00:04:06.250 --> 00:04:10.750 and press minus on the keyboard NOTE Treffsikkerhet: 91% (H?Y) 00:04:10.750 --> 00:04:13.250 and then NOTE Treffsikkerhet: 87% (H?Y) 00:04:13.250 --> 00:04:22.200 find the mean of the variable. So V mean is the variable mean of which variable, i have to say which 00:04:22.200 --> 00:04:31.900 variable, of the same variable. So this says the value of this variable, minus the mean of the variable, NOTE Treffsikkerhet: 82% (H?Y) 00:04:31.900 --> 00:04:38.100 the same variable, in this case I could have used another one for another formula. And now I want all 00:04:38.100 --> 00:04:44.400 of these divided by the standard deviation, well the do something with all of this as one thing I 00:04:44.400 --> 00:04:50.700 have to enclose it in parentheses, so i have to go around and type, and opening and closing parenthesis, 00:04:50.700 --> 00:04:59.600 now this difference becomes one thing, and I can divide it pressing on the division symbol, I can 00:04:59.600 --> 00:05:01.650 divide by the variable standard deviation, NOTE Treffsikkerhet: 69% (MEDIUM) 00:05:01.650 --> 00:05:04.950 which is this function. NOTE Treffsikkerhet: 82% (H?Y) 00:05:04.950 --> 00:05:12.500 And I need to specify which variable goes in here, and it's again this same variable, so now I have 00:05:12.500 --> 00:05:19.500 divided the difference from the mean by the standard deviation, I can press enter and of course let 00:05:19.500 --> 00:05:26.600 me push this up, and you see these numbers are the same as these ones, of course because we use the 00:05:26.600 --> 00:05:33.900 formula for the Z score here, and the direct function to get a z-score here, and they are exactly the 00:05:33.900 --> 00:05:34.600 same. NOTE Treffsikkerhet: 85% (H?Y) 00:05:34.600 --> 00:05:42.400 So you can use the direct function Z whenever you need to compute a z-score in Jimovie. NOTE Treffsikkerhet: 88% (H?Y) 00:05:44.700 --> 00:05:52.400 How about Computing a scaled score from these values, this is very easy we just have to apply the 00:05:52.400 --> 00:05:59.200 corresponding formula. Let us remove this condom by clicking on delete, NOTE Treffsikkerhet: 91% (H?Y) 00:06:00.100 --> 00:06:03.900 and now click compute NOTE Treffsikkerhet: 91% (H?Y) 00:06:05.300 --> 00:06:11.700 to create a scaled score let's call it NOTE Treffsikkerhet: 87% (H?Y) 00:06:11.700 --> 00:06:16.700 scaled score matrices 0k NOTE Treffsikkerhet: 91% (H?Y) 00:06:18.900 --> 00:06:29.200 and say these scaled scores with a mean of 100 and a standard deviation of 15, NOTE Treffsikkerhet: 72% (MEDIUM) 00:06:30.500 --> 00:06:40.100 so use the z-scores that we have already computed, you always have to go through Z scores in order to 00:06:40.100 --> 00:06:46.900 produce scaled scores because that's where the information is about how many standard deviations 00:06:46.900 --> 00:06:50.800 above or below the mean each value lies at. NOTE Treffsikkerhet: 91% (H?Y) 00:06:50.800 --> 00:06:59.400 So the first thing we need to do is multiply the z-scores with the desired standard deviation, so by 00:06:59.400 --> 00:07:06.200 15, and then add the desired mean so plus 100. NOTE Treffsikkerhet: 80% (H?Y) 00:07:06.200 --> 00:07:16.700 And these are our scaled scores, scale scores are always reported as integers, so to this formula we 00:07:16.700 --> 00:07:18.800 need to add NOTE Treffsikkerhet: 89% (H?Y) 00:07:18.900 --> 00:07:31.850 a way to remove the decimal places and use the int function, which converts a number to an integer. 00:07:31.850 --> 00:07:39.200 What we need to do is we need our original formula to be inside the parentheses, so I deleted the 00:07:39.200 --> 00:07:45.950 closing parenthesis from there, and I type one at the end. So everything goes inside int, NOTE Treffsikkerhet: 91% (H?Y) 00:07:45.950 --> 00:07:56.050 and now they're all integers as expected. And so this is the conversion of these raw scores expressed 00:07:56.050 --> 00:08:06.250 in an IQ type scale with a mean of 100 and a standard deviation of 15, if we wanted to have a scaling of 00:08:06.250 --> 00:08:13.300 the mean of 10 and a standard deviation of three we would multiply by 3 and then add 10 instead.