Unlike wide format datasets that give each session its own row, long format gives each prompt in a session its own row. Long format datasets provide more detailed information about each prompt. This additional information includes Prompt Response Lapse, Order in Session, the Prompt Type and Prompt Text (see Dataset Definitions). Long format data downloads can report Prompt Response Lapse in Milliseconds if that option is selected in the download modal.
Also, unlike wide format datasets, long format is not set up for multilevel modeling.
For more information about the differences between long and wide format datasets, please see this article.
(Note: The use of the terms long and wide format for intensive longitudinal studies differ slightly from longitudinal studies. For more information, please see this article.)