To join two files in Excel so that participants from Study 1 are next to the same participants from Study 2, you can use the VLOOKUP function. Here are the steps:
Open both files in Excel.
Make sure that the participant ID is present in both files and is in the same format.
In one of the files, insert a new column to the right of the participant ID column.
In the new column, use the VLOOKUP function to look up the participant ID in the other file and return the data you want to join. For example, if you want to join a variable called "score," the VLOOKUP formula would look something like this:
=VLOOKUP(A2,[study2.xlsx]Sheet1!$A$2:$B$100,2,FALSE)
where A2 is the cell containing the participant ID in the first file, [study2.xlsx]Sheet1!$A$2:$B$100 is the range of data containing the participant IDs and scores in the second file, 2 indicates that you want to return the second column (i.e., the scores), and FALSE indicates an exact match.
Copy the VLOOKUP formula down to all the rows in the first file.
Save the first file under a new name to preserve the original data.
Open a new blank workbook and copy and paste the data from both files into this new workbook. Make sure that the participant ID column is next to the joined data.
Sort the data by participant ID to make sure that the participants from both studies are lined up correctly.
Save the new file as a new name to preserve the joined data.
With these steps, you should now have a file that combines the data from both studies, with the participants lined up correctly.