Variables, Measures, and SPSS


Let's learn about SPSS, the requiring software for use in this class. The topics we'll cover in this presentation include file types, how to enter data, and how to copy data and or output from SPSS to place into your Word document Homework file. Several types of files will be used in this course. Understanding the file extension types can save you time and frustration when trying to figure out how to open the files. File extension is shown at the end of the file name after the dot. The three types of files used in this course are shown on the screen. Word documents will be used for homework files. You will submit all of your homework as a Word document ending with a dot DOC or a dot DOCX. Spss is software you must install on your personal computer for use in this class. It will be used to conduct your statistical analyses. You will have data files that end in dot SAB and then your output will be placed into separate types of files, the SPSS output files, they ended in dot SPV, although earlier versions would end in dot SPO. After you've installed SPSS, you can open it. When you open SPSS, there will be two windows. One is the data file. This is the one that ends in extension dot S-A-V-E, as previously discussed. Let's start with this data file. This is the one that is shown on your screen right now. This is what the data file will look like if you create a new file. Notice that the bottom there are two tabs, a data view and the variable view. The data view is where you enter your data. The variable view is where you can specify variable information like the name, its scale of measurement, and any labels or codes. Let's start with the data view, which is shown on this slide. Each column temporarily labeled as they're typically represents a variable. Each row. Example where you see one all the way across, typically represents a participant's data. As just stated, the data view is where you would enter data as shown in this slide. I've entered data on two variables for ten participants. Ten participants is shown by counting the number of rows, which SPSS syntax for us. The two variables are demonstrated by having two columns. Now this won't always hold true, but it does for now. When using SPSS, we also want to code all variables, which means convert them to numbers. For instance, my first variable is actually sex. I have just coded the males as zeros and females as one. This is because SPSS can only analyze numerical data, so we convert them all to numbers that is called coding. My second variable is anxiety scores with higher indicating high levels of anxiety. However, the variable names as shown on this screen, is very zeros, zeros, zeros 0,100,000.0 to, let's fix this. To do this, we would click on the tab that says Variable View. This is what variable view looks like. The data is no longer shown. Instead, the variable information is shown. Now at this screen, there's no way to tell how many data points you have, only how many variables you have. There is one row per variable and the variable view, we can simply click in any of the boxes to modify its contents. And many of your assignments in this course, you will be told what to name your variables. To change your name, go to the column with the heading name, and click on whichever variable you want to rename. You cannot have spaces in your names. So for this example, we will want to rename variable one is sex and variable to as anxiety. Finally, for now, we will want to change the scale of measurement for each variable. We do this by going into the column with the heading measure. You can then drop down to select nominal, ordinal or scale. Remember scale is interval or ratio data. You can then go to the top and click on the tab that says File and then Save to save your data file. You will be selecting a variety of these tabs throughout the course. Most often analyze to select a specific statistical analysis or graphs to create a graph, the tab help is a great resource if you get stuck or have a question. To show what output looks like, I'm going to go ahead and select the tab, Analyze Descriptive Statistics, then explore. Now I'm going to click on anxiety. It is highlighted. And then I will click the arrow to move it to where it says Dependent List. Next, I would click on sex, and when it is selected, I will click the arrow to move it to the factor list. Now I will select, Okay, this is a point and click method we will be using in class. You simply point to what you want and click to have SPSS from the analysis. Our output file will then come up on our screen. And the left-hand panel, we can select anything in our view, will jump to that location to demonstrate how to copy and paste a graph into Word. I'm going to select where it says boxplot. You will find copy and paste feature works similarly on any type of output. In this example, I'm using a PC. I simply right-click on the graph and select Copy. I can then open my homework file, that is a Word document, and right-click to paste it into the document. Depending on what version of a PC you have. This may distort your image or the paste will not fit. You have several options. When you right-click, you can instead select Copy Special, then select image, making sure to unselect all other options in your SPSS output window. This will allow you to more easily resize it once you've pasted it into your Word document. Another option is to paste special when within the Word document to try out the various options to see what looks best fits within your document. You should have similar options for Mac, but Max also allow a screenshot using a keyboard command Shift, Command four. You cannot copy and paste your data file into a Word document. So sometimes you will want to do screenshots. You can use screenshots and PCs and Macs to copy information from both the SPSS data files and the output files, but needing to move them to your homework file. For instance, if asked to show your data view, you would open it so that you can see what you want to transfer. You would also have your homework document that's in Word opened but minimized. You would then follow the directions on this slide for whether you are using a Windows or Mac operating system has shown above. I realized SPSS may seem a bit overwhelming. It is similar to learning a new language. The more time you spent immersed in it, the quicker you will become familiar with it. Your assigned readings, how data you can enter yourself and practice to compare your output to that provided in your readings. I highly encourage you to take the time reviewing those examples before beginning any homework exercises. This concludes the presentation introducing you to SPSS. I encourage you to now go and practice, practice, practice.