This is a step-by-step guide on how you, as a study participant, install and use the CARP Studies app. If you are new to CARP, you can read more about the Copenhagen Research Platform and the Department of Health Technology at the Technical University of Denmark, which hosts CARP and is responsible for CARP studies.
The app has a new design. Here is the whole first-time flow, recorded on an Android phone. It takes about three minutes.
To use the CARP Studies app, follow these steps:
- Install the app on your phone (iPhone or Android).
- Join the study, with a QR code, a short code, or the account you received by email.
- Accept the study invitation.
- Learn about the study and give the app the permissions it needs.
- Read the informed consent and sign it.
- Navigate the app.
- Connect wearable devices, if your study uses them.
- Do the study tasks.
In the following, we describe each step.
1. Install the CARP Studies app
First, update your phone to the latest operating system: update your iPhone or update your Android phone.
If you have an older version of the CARP Studies app, delete it first: long-press the app icon and tap “Uninstall” (Android) or “Remove App” (iPhone).
Then download and install CARP Studies from the App Store or Google Play. You can also scan these codes with your phone camera.
2. Join the study
When you open the app, it asks “How were you invited?”. How you join depends on the study. Pick the option that matches what you received from the study team.
| You received | Choose | What it means |
|---|---|---|
| A QR code or a 5-character code, for example on a poster, at an event, or from the study team | I have a QR code or a short code | You join anonymously. You don’t need an email or a password. |
| An email invitation to the study | I have a username and password | You sign in with your own CARP account, so the study team knows who you are. |
Joining with a QR code or a short code
Allow the app to use the camera and point it at the QR code. If you have a short code, switch to the Code tab and type the 5 characters.
Joining with a username and password
When a researcher invites you by email, you receive an email asking you to create a CARP account (unless you already have one). Click the link in the email and enter your first and last name and a password. Write down your username (your email address) and password, because you need them to log in to the app.
In the app, choose I have a username and password and log in with that email and password. On iPhone, you may first be asked to allow the app to sign in via the “carp.dk/” domain.
3. Accept the study invitation
The app now shows the study invitation: the study purpose, your role (for example “Participant”) and this device (your smartphone). Tap Accept.
4. Learn about the study and allow permissions
A few short screens explain the study. Each has a Learn more link. The texts come from the study itself, so your study shows its own words.
Part of taking part in a study is that some data is collected automatically by the phone and its sensors, without you having to do anything, for example location and steps. The app therefore asks for the permissions the study needs, one at a time, each with a short explanation of why. Depending on the study, these can be:
- Location
- Physical activity (fitness and motion), for steps and whether you are walking or still
- Microphone and camera, for audio, video and photo tasks
- Notifications, so the app can tell you when a task is ready
- Health data from Health Connect (Android) or Apple Health, such as activity, steps, sleep and heart rate
- Bluetooth (“Nearby devices”), if the study uses a wearable
- Running in the background. On Android, the app asks you to stop battery optimization, so data collection continues when the app is closed.
Please allow everything the study asks for. You can say no to a permission, but the study then collects less data.
A special note on location: the app needs your location also when you are not using it (in the “background”). Please choose “Allow all the time” (Android) or “Always” (iPhone). The app does not reveal your exact location. It uses the location to calculate higher-level features, like how much time you spend at home or how much you travel during a day. You can read more about how we collect and handle data in the app’s privacy policy.
5. Read the informed consent and sign it
Next, the app shows the informed consent form, which contains all the relevant information about the study. Read it carefully. When you have read the summary, tap Agree if you consent. Then write your first and last name and sign with your finger. You will see “Consent saved”. Tap Done.
You can download your signed consent later from the Home page.
6. Navigating the app
You are now ready to use the app day to day. It has four pages, which you open from the menu at the bottom. Your profile is the round icon at the top right.
| Page | What it is for |
|---|---|
| Home | The study you are in, how many data sources are connected, your progress (days in the study, tasks done and pending) and messages from the study team. About the study shows the study description, privacy policy, who to contact and your signed consent. |
| Tasks | The things the study asks you to do, such as surveys. |
| Statistics | Charts of your own data, for example tasks completed, heart rate, sleep and steps. Which charts you see depends on the study. |
| Connections | Your phone, the wearable devices you can connect, and the services the study uses, such as location, weather, air quality and Health Connect or Apple Health. |
7. Connecting a wearable device
Some studies ask you to connect a wearable device via Bluetooth, for example a heart rate monitor such as Polar or Movesense. Open the Connections page, find the device and tap Connect, then follow the instructions on the screen.
Make sure Bluetooth is turned on in your phone’s settings.
8. Doing study tasks
You will use the Tasks page regularly during the study. It has two lists, Pending and Completed. Each task shows what kind of task it is, how long it takes, and how much time is left. Tap Start to begin.
Tasks can be surveys, short cognitive tests (like a tapping or reaction-time test), voice or video recordings, or photos. In a survey, some questions use sliders: slide to the number that matches how you feel. Others are multiple choice: select the answer or answers that fit best. The survey shows how far you are (for example “3 of 8”). Tasks can have a deadline. A task you don’t finish in time expires.
Leaving the study
Open your profile. Leave study stops the study on this phone. Sign Out leaves the study and signs you out.
Now you’re familiar with the app! We hope you enjoy using it while you take part in a CARP study. Questions? Contact the study team. You find their details under About the study on the Home page.