Skip to content

Longitudinal Projects and DAGs

Longitudinal Projects & Data Access Groups

Article ID RC-DE-03 — Longitudinal Projects & DAGs
Domain Data Entry
Applies To REDCap projects with Longitudinal mode or Data Access Groups enabled
Prerequisite RC-DE-01 — Record Creation & the Record Home Page; RC-DE-02 — Basic Data Entry
Version 2.0
Last Updated 2026-05-11
Author See KB-SOURCE-ATTESTATION.md
Related Topics RC-DE-09 — Data Entry with Data Access Groups; RC-DE-10 — Longitudinal & Repeated Data Entry; RC-NAV-REC-02 — Longitudinal Mode & Arms; RC-NAV-REC-04 — Record Status Dashboard & Other Record Links; RC-DAG-01 — Data Access Groups

Navigation article. This article orients you to two features that change the data entry experience — Longitudinal mode and Data Access Groups — and points you to the dedicated articles for each. If you already know which feature you need, jump straight to the relevant article below.

1. Overview

Two optional project features significantly affect how data entry works in REDCap:

Longitudinal mode allows the same instrument to be reused across multiple timepoints (events) within a record. The Record Home Page changes from a simple list to a grid where rows are instruments and columns are events. Each cell in the grid is an independent data entry. → Full coverage: RC-DE-10 — Longitudinal & Repeated Data Entry

Data Access Groups (DAGs) partition records into named subsets — typically one per study site or department. When DAGs are enabled, you can only see and create records within your own group. Records from other DAGs are invisible to you. → Full coverage: **RC-DE-09 — Data Entry with Data Access Groups

These features are independent — a project can use one, both, or neither. When both are active, longitudinal mode changes the record layout while DAGs filter which records you can see. They do not interfere with each other.

2. Where to Go from Here

I need to… Go to…
Understand the grid layout, events, and arms in a longitudinal project RC-DE-10 — Longitudinal & Repeated Data Entry
Understand repeated instruments or repeated events RC-DE-10 — Longitudinal & Repeated Data Entry
Understand why I can only see certain records RC-DE-09 — Data Entry with Data Access Groups
Switch between DAGs (DAG Switcher) RC-DE-09 — Data Entry with Data Access Groups
Understand how arms and events are structured RC-NAV-REC-02 — Longitudinal Mode & Arms
Understand how DAGs are set up and managed RC-DAG-01 — Data Access Groups