Transcript

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Adding variables into jamovi. This tutorial will show you how to create variables and add data into jamovi. Using a simple example, let's imagine that we want to investigate the phenomenon of social facilitation. Our simple hypothesis might be that participants perform better on a simple task when in the presence of others.

To test this hypothesis, we could create two experimental groups. Group 1, audience present, participants perform a task while being watched by an audience. Group 2, audience absent, different participants perform the same task alone.

We could call this variable audience presence, and it will be our independent variable. We would then need to measure participants performance in some way. For this example, let's consider a simple task that involves participants being asked to write down as many words as possible that begin with the letter F in 60 seconds. The number of words generated would therefore be the dependent variable. The two groups performance could then be directly compared.

Defining variables. First, let's open jamovi. Before we add our data, we need to tell jamovi what information we collected, so we need to define our variables. To do this, you need to click on variables, which is the first menu on the toolbar at the top of your window.

Jamovi automatically provides three variables titled A, B, and C, under variable view. To edit these variables, you can either double click on a variable or select a variable and click the Edit button as shown.

Alternatively, to add a new data variable, you can click on the Add button at the top and select Insert to insert a data variable between the current variables, or Append to insert a data variable at the end. Double clicking a variable, clicking Edit, or adding a new variable will all reveal the data variable box.

Defining our independent variable as audience presence. The first thing we need to do is set up a variable to indicate whether an audience was present or absent. In the variable view, select the first variable currently called A and click Edit.

The variable is currently called A but we want to replace this with something meaningful. The name you choose will appear at the top of the corresponding data columns in the data view sheet. As such, you don't want to give your variables long names as this makes them difficult to read.

For this example, we will call the variable audience presents. Under the title box, we have the option to include a description. This can be helpful if you have a large number of similar variables, but for this example, we will leave it blank.

Next, we have measure type. The measure column allows us to tell jamovi what type of variable we are entering data for. You would select continuous if you are entering interval or ratio data, that is, where the difference between scores on the scale is meaningful and standardized, and intervals across the scale are equal.

Ordinal, if you have a categorical variable where the order of the categories matter. Or nominal, if you have a categorical variable where the order of categories does not matter. In our example, we need to select the nominal option as we are looking at a categorical variable, which is audience present versus audience absence without obvious ordering.

Next, we have data type. Here you can change the type of data that is associated with the variable. We have three options, integer. Integer variables in jamovi are designed for values that can only be whole numbers. This contrasts with decimal variables, which can include decimal points and fractions.

For example, IDs such as the student ID number or ordinal scales where numbers represent ordered categories. For example, 1 for strongly disagree, 2 for disagree, and so on. Decimal represents numerical data with decimal points, indicating the presence of a fractional part. It's used for values that are not whole numbers.

Text variables are often used to represent categories or labels, such as names, locations, or descriptions. For example, a variable might hold the name of different cities or the different responses to a survey question. For our variable audience, we could select text as our data type. This allows us to write present or absent to represent each of our conditions when inputting our data.

After you've done this, your data variable window should look the same as shown. Now, we need to tell jamovi what our conditions are for this variable. You can see a box titled levels and a plus sign to the bottom right hand side. Click on the plus sign.

This will bring up a box asking us to enter level value. This is where we input each of our conditions. To represent our condition where the task is being completed with an audience present, we want to type present and click OK.

Then click on the plus sign again to enter our second condition. This time we want to represent the condition where the task is being completed without an audience present. So we will type absent and click OK.

Defining a dependent variable, words. Once we've entered the information for our first variable, we can enter in the details for our other variables. Let's move on to our dependent variable, which is the number of words each participant wrote down in 60 seconds.

Either double click on variable B or select variable B and click the Edit button as shown. For the title, we could put words. Under Measure Type, we would click on Continuous as the difference between scores on the scale is meaningful and standardized, and intervals across the scale are equal.

For data type, we would select integer as participant scores will be whole numbers. We do not need to add any levels for this variable as it is not categorical. When you've done this, your dependent variable words should look like this.

Defining demographic variables. When carrying out research, it's also important to collect demographic information about your participants, especially age and sex. These variables also need to be defined so we can enter the data into our data sheet.

Let's edit the C variable and title it sex. The measure type would be nominal as sex is categorical. For data type, we can select Text again. So we can input our sex data as words, e.g. male or female.

We could define our categories in this variable by clicking the plus sign to the bottom right hand side of the box titled levels. We would enter male for our first category. Then click the plus sign again to enter female. When you've done this, your sex variable should look like this.

Finally, let's define age. Insert a new variable and title it age. The measure type for age would be continuous. For data type, we will select Integer as we usually collect age in whole years, for example, 23 rather than 23.4. Your age variable should look like this.

Entering data. Once you've added all four variables, this is how your variable window should look. Now we can start entering in our actual data. To do this, click on Data, which is the second menu on your toolbar at the top of your window. This will take you to the data spreadsheet.

Notice how the headers of the columns have now changed to display the variable names. They should now read audience presence, words, sex, and age. When entering data into jamovi, it is important to follow the simple rule of thumb, each row represents an individual participant, observation, or case.

When you enter data, the number of rows should be the same as the number of participants you have. If you find yourself entering data from the same participant on more than one row, or entering data from many participants on only one row, the chances are you are entering it incorrectly. In this case, you need to enter the data in the following way.

Enter in present or absence in the audience column to represent whether the participant completed the task with an audience or without. The numbers entered into the words column are the number of words participants wrote down. Enter male or female into the sex column.

The number entered into the age column, the participant age in years. Have a go at entering the data into your own spreadsheet. Once you are done, it should look like this.

You have now finished entering your first set of data. Once you've finished creating your data file, you need to save it. To do this, click on the File menu, which is three horizontal lines at the top of the left hand side of your window. Then select the Save option or Save As and name your file in the usual way.

Now you have completed the first three tutorials, Getting Started, Menus, and Adding Variables, why not explore the program further yourself? Try adding some data and seeing what you can do with the different menu options. You don't need to worry about breaking jamovi. The worst case scenario is that you produce some meaningless output, but that's just part of learning how it works.