Step-by-Step Guide 3:

Create a new Dataset & add Variables

Overview: Building your Dataset & Add Variables

Before we can start analysing our data, it is important to build our dataset and/or to get datasets you have downloaded ready for use.  Don't assume that downloaded datasets are ready for analysis. You may have to add labels, descriptions and missing values to your variables. 

It is really important to become familiar with your dataset, so spend some time looking at the codebook. This will help you identify your labels and missing values.  These steps are really important, so don't skip them. 

What you will learn here:

Once you have followed the steps below your dataset will be ready for use.  Jamovi sets out the data exactly like an Excel spreadsheet - in rows and columns.

Columns: Each represents a variable (e.g. Gender, age, or answers to a question like 'On a scale of 1-5, how much do you like ...?')

Rows: Each row represents a set of observations. (E.g. for participant 1, based on the variables mentioned above it would be: Male, 34, 4).

Keep this in mind when working with your data.

Variables Types

Variable Types: 

One important task is to assign the correct data type to your variables. Below is a quick overview of the options you have.

Data Types information:  

Once you have selected the type of data your variable is Jamovi will usually automatically select the format your data type has. Below is a summary.  On rare occasions, you may have to adjust them. 

Integer: 

These are full numbers e.g. 1, 2, 3, ... 1000, etc - Integers can be used for all three types of data. When used for Nominal/Ordinal data numbers will represent labels e.g. Green - 0; Yellow - 1; etc.

Decimal: 

These are numbers with decimal points. e.g. 1.3, 5.6, 7.8, etc - This will usually only be used for continuous data.

Text: 

This can be used for Ordinal and nominal data. Note, if there is text you will be unable to use this variable in a variety of tests that require numbers. 

ID or Index: 

This will usually be your first column. This will be a unique identifier for each column. This can be text or numbers, but it should be unique to each row. 

ID columns should never be used in any of your tests. 

Video: Variables Types and Levels

Create a Blank Dataset

1.

Open Jamovi

Unless you open a pre-existing file, Jamovi will open a blank dataset for you. All you need to do is modify and/or add variables.

If you already have a file open follow the steps below:

Menu > New

You now have a blank dataset

2.

Menu > New 

If you already have another file open do the following:

Menu > New

This will create a blank dataset for you. Now you can start creating new variables.

Create/Modify New Variables

1.

Modify Variables

Double-click on a pre-existing variable > Add information 

Variable Name: Update our variable name - keep this short and avoid sentences

Description: Add any additional information about the variable e.g. What question was asked, how is it measured etc.

Data Type: Unless there is an error, don't change this.

We will show you how to add missing values and levels further down.

2.

Adding new Variables

There are three ways of adding new variables

First way: 

Double-click on blank column > New DataVariable

Variable Name: Add your variable name - keep this short and avoid sentences

Description: Add any additional information about the variable e.g. What question was asked, how is it measured etc.

Data Type: Unless there is an error, don't change this.

We will show you how to add missing values and levels further down.

Second Way:

Data Tab > Add > Insert or Append

Now you can add the variable information as outlined in the previous steps. 

Third way: 

Select the variable you want your new variable next to > Right-click > Add Variable > Insert or Append

Now you can add the variable information as outlined in the previous steps. 

Add Variable Levels

1.

Double-click variable > Click +

Double Click Variable > Click on + on the right of the Levels box

2.

Add Levels & Labels

In the box enter your numeric value/text> Ok

Note: You can add text, but then you will be unable to carry out certain tests. 

Select Level to label > click on the number > Enter label 

Now all of your levels should have labels.

Add Missing Values

1.

Add Missing Values

Jamovi automatically recognises blank fields as missing values - no further action is needed unless you have other values that should be considered missing. 

In many datasets, missing values are indicated by a number such as -99. Or you may want to exclude certain data from your variable (e.g. Other).  Make sure you check your data, as you will have to tell Jamovi what values you want to exclude (be recognized as missing).

You can easily update the missing values for multiple variables at the same time. 

Note:  Always make sure Jamovi knows your missing values - failure to do so, can seriously screw up your results.   

Select variable > Double-click on it > Missing Values

2.

Missing Values > Add information 

Click in the Missing Values Field. You can now select the ground of excluding values. This can be typed in or you can select it from the dropdown menu (access it by clicking on the tiny little downward arrow).

Now enter the value. If your variable is a text variable use ' ' to enclose any text. If your variable has levels you can either use the number or the label, again encloses it in ' ', but make sure it is spelt correctly. 

You can add additional missing values by selecting Add missing Values at the bottom. 

Your missing values should now appear greyed out. 

3.

Apply Missing values to multiple variables

To add the same missing values to multipe variables at the same time, simpley select all of the variables you need.

Select first Variable > Press Ctrl on PC or cmd on Mac and select further variables

Follow Step 2 to exclude your missing data.

Enter Data

Most of the time, you won't have to enter data into Jamovi, as you can just import your dataset from Excel. However, if you have run a paper-based survey, you will have to manually create your dataset. Use the steps above to create your variables and then enter your data manually. 

Other times you may already have a dataset, but you may want to add a variable manually (maybe you are getting additional information from somewhere else). 

1.

Select Variable > Enter Data

Double-click on the variable you want to enter data into. Check the levels. You are now ready to enter your data. 

Important: If there are levels in place you can either enter the number or the label text - Do make sure you spell it correctly (including capitalisation as it will create a new level if you get it wrong). 

Click in Cell > Enter data

Now repeat this until your data is entered. 

2.

Copy and Paste Data into a Variable

Sometimes you may already have your data in another document. As long as it takes the same format or is comma-separated (e.g. 1,2,0, etc) then you can paste your data into Jamovi. 

Select Variable > RIght-click > Paste (ctrl+v on PC or cmd+v on Mac)