Step 1: Design your study

What you’ll do: write the study protocol from Configure your study in Dart, the recipe your app will follow. It answers four questions:

Question	In the protocol	In this example
Where is data collected?	Device	The phone
What is collected?	Measures	Steps and battery
When is it collected?	Trigger	Right away, all the time
Where does data go?	Data endpoint	A database on the phone

Steps

1. Create the protocol and choose where data goes.

   final protocol = SmartphoneStudyProtocol(
     name: 'My first study',
     dataEndPoint: SQLiteDataEndPoint(),
   );

2. Add the device and the participant. The phone collects the data; the participant is the person using it.

   final phone = Smartphone();
   protocol.addPrimaryDevice(phone);
   protocol.addParticipantRole(ParticipantRole('Participant'));

3. Say what to collect, and when. ImmediateTrigger means “start right away”; BackgroundTask means “keep collecting quietly”.

   protocol.addTaskControl(
     ImmediateTrigger(),
     BackgroundTask(name: 'Steps and battery', measures: [
       Measure(type: SensorSamplingPackage.STEP_EVENT),
       Measure(type: DeviceSamplingPackage.BATTERY_STATE),
     ]),
     phone,
   );

You’ll put this code into the app in the next step.

Tip

Want data every hour instead, or a survey every morning? That’s a different trigger or task. All options are in Study Protocol.

Check it

You can answer the four questions above for your own study. If you’ll use CAWS, the protocol is usually created in the CARP Portal instead of in code. That’s covered in Step 3.

Next: Step 2: Build the app