Step-by-Step Guide to Converting Long to Wide Data in SPSS

Introduction

In SPSS you can use the LONG TO WIDE function to transform long‑format data into wide‑format data. The function is located under the Data tab in the menu bar and can be accessed by following these steps:

Open the dataset in SPSS.

Click the Data tab in the menu bar.

In the Data tab, click Restructure and select LONG TO WIDE . In the dialog that opens, choose the variables to use, set other options, and click OK to perform the conversion.

Example

Long‑to‑wide data conversion is a common operation in SPSS, known as data restructuring.

Repeated measurement data often appear in a single column, with each measurement (y1‑y4) representing the same indicator. The goal is to merge these into a single column of y values, adding a new variable to indicate the measurement order, called an index in the restructuring wizard.

Other existing variables remain unchanged. This process converts wide data to long data.

In SPSS, the menu path is: Data → Restructure . Follow the wizard step‑by‑step.

The first module handles wide‑to‑long conversion; select it and click Next .

Select the first measurement (y1‑y4) as the variable to be merged and proceed.

Assign a name to the target variable (e.g., y) and place the four repeated measurements into this field.

You also need to define an identifier variable. If the data already contain an ID, use it; otherwise SPSS will create a case number automatically.

Other settings can remain unchanged; click Next .

Since only one indicator (y) is measured repeatedly, a single index is required.

Specify the index variable label, preferably using numeric coding.

Finally, click Finish → OK .

Originally each person occupied one row (8 rows). After converting, each case occupies four rows, resulting in 32 rows (8 cases × 4 measurements).

The index represents the order of repeated measurements; the variable y is the measured indicator.