Chapter 4 Aggregating data: mean
A common task is aggregating multiple variables (columns in a dataset) into one new variable (column). For example, you may want to compute the average score on the items of a questionnaire.
Note that when creating new variable names, it is important to follow the convention for variable names (see section (software-basics-file-and-variable-name-conventions)).
4.1.1 Example dataset
From this dataset, this example uses variables
We will aggregate these into the variable
highDose_attitude (note that this variable already exists in the dataset, and that existing variable is also the mean of those five variables).
4.2 Input: jamovi
In the “Data” tab, click the “Compute” button as shown in Figure 4.1.
Type in the new variable name in the text field at the top, labelled “COMPUTED VARIABLE”. Then click the function button, marked \(f_x\), select the MEAN function from the box labelled “Functions”, and double click all variables for which you want the mean in the box labelled “Variables”, while typing a comma in between each variable name as shown in Figure 4.1.
Alternatively, you can type the function name and list of variables directly without using the function (\(f_x\)) dialog as shown in Figure 4.2.
4.3 Input: R
4.3.1 Base R
4.4 Input: SPSS GUI
First activate the
dat dataset (see 2.4.1).
4.5 Input: SPSS Syntax
COMPUTE highdose_attitude = MEAN( highDose_AttGeneral_good, highDose_AttGeneral_prettig, highDose_AttGeneral_slim, highDose_AttGeneral_gezond, highDose_AttGeneral_spannend ).
Aggregating variables is not an analysis, and as such, does not produce output. You can inspect the newly created variable to ensure it has been created properly.