Confusion in terms in "Long" and "Wide Format" for longitudinal and intensive longitudinal studies.

The terms wide and long format datasets are used slightly differently in intensive longitudinal (IL) and longitudinal studies (see 1, 2, 3). Although IL and longitudinal studies are related, they differ in their purpose, and thus, data processing. In this article, we’ll explain the difference in terminology.

In IL studies (LifeData datasets), each row is an individual prompt for long format, while in wide format each row is a participant’s session.

However, longitudinal studies call their datasets that are organized by putting each year (session) for an ID a row long format, and datasets giving each ID a row and each year/variable (session/prompt) a column wide format.

Although there is a little confusion between terminology IL and longitudinal studies, it is quickly cleared up when you look at how each type organizes its data.

 

 

Wide

Long

Intensive longitudinal

Each session has a row

Each prompt has a row

Longitudinal

Each ID has a row

Each session has a row

 

 

Prompt

Session

ID

Intensive Longitudinal

Long

Wide

NA

Longitudinal

NA

Long

Wide

 

Have more questions? Submit a request

Comments