Introduction

In Version 4.0 of the platform, Metricwire introduced several new sensor capabilities. Sensors allow you to capture objective data on your participant's activity or location and use this data to engage participants based on context. Given the sheer volume of data that can be captured using sensors, Metricwire offers sensor capabilities as an add-on to the core platform. If you are interested in trying sensors in the Metricwire platform or have a project in mind, get in touch with us through our website or contact customer success.

Available Sensors

Here is a list of available sensors in Version 4.0:

Sensors	Brief Description	Variables	Learn More	iOS
				Platform Availability
Activity Type	This is a classifier that applies an algorithm to raw sensor data to predict the type of user activity being performed.	MotionType: The type of motion that is being performed: Stationary, Walking, Running, Automotive, Cycling, Unknown. Accuracy: The confidence in the assessments of the motion accuracy. Low: 1 Medium: 2 High: 3	More Details
Gravity	The acceleration effect of the Earth's gravity on the users device.	The gravity acceleration vector expressed in the device's reference frame: x y z	More Details
Linear Acceleration	The acceleration effect that the user is giving to the device by physically moving it.	Acceleration that the user is giving to the device The following data points will be collected: x y z	More Details
Accelerometer	An accelerometer sensor reports the acceleration of the device along the 3 sensor axes. The measured acceleration includes both the physical acceleration (change of velocity) and the gravity.	Acceleration that the user is giving to the device The following data points will be collected: x y z	More Details
Gyroscope	A gyroscope sensor reports the rate of rotation of the device around the 3 sensor axes.	A gyroscope measures the rate at which a device rotates around a spatial axis. x y z	More Details
Magnetometer	A magnetic field sensor (also known as magnetometer) reports the ambient magnetic field, as measured along the 3 sensor axes.	Provide compass-level orientation data and raw magnetometer data. x y z	More Details
Altimeter	The altimeter measures changes in altitude (relative) and the current pressure (kPa).	Relative Altitude: The change in altitude (in meters) since the first reported event. Metrics: relativeAltitude Pressure: The recorded pressure, in kilopascals. Metrics: pressure	More Details
Pedometer	The pedometer measures the amount of steps taken in a given time and can calculate total walking distance by averaging stride length.	Start Date: The start time for the pedometer data. Metrics: startDate End Date: The end time for the pedometer data. Metrics: endDate Number of Steps: The number of steps taken by the user. Metrics: numberOfSteps Distance: The estimated distance (in meters) traveled by the user. Metrics: distance Average Active Pace: The average pace of the user, measured in seconds per meter.Metrics: averageActivePace Current Pace: The current pace of the user, measured in seconds per meter. Metrics: currentPace Current Cadence: The rate at which steps are taken, measured in steps per second. Metrics: currentCadence Floors Ascended: The approximate number of floors ascended by walking. Metrics: floorsAscended Floors Descended: The approximate number of floors descended by walking. Metrics: floorsDescended	More Details
Ambient Temperature & Light	The ambient temperature & light sensors sprovides the room temperature in degrees Celsius. A ambient light sensor reports the current illumination in SI lux units.	Ambient Temperature: Ambient (room) temperature in degree Celsius. Metrics: temperature Ambient Light: Ambient light level in SI lux units Metrics: light	More Details
Location Tracking	Passively collect the GPS coordinates of the participant at any point in time.	Latitude: The latitude of the device. lat Longitude: The longitude of the device. lon Hold Position: This is set to true if the location was before the target range to track on. holdPosition Accuracy: GPS Error Estimate. accuracy Speed: Device speed in meters per second. Not always available. speed	More Details

Configuring Sensors

Step 1 - Navigate to the sensors tab

Once sensors have been enabled in your account, a new 'sensor' tab will be added to the top bar in your study. Here is what to expect:

Step 2 - Toggle a sensor on

Click the toggle to reveal the sensor settings.

Step 3 - Add A Trigger

Click on 'Triggers' and then 'Add Trigger'

Step 4 - Define your trigger settings

Metricwire's sensors use our existing trigger technology. This means you can create incredibly complex tracking schedules with very little effort. Here are a few examples:

Continuous Tracking

To set up continuous sensor tracking, use an ongoing trigger.

Random Sampling

To randomly sample the sensor, simply use a random trigger and define your sampling window. Here we see ten 30 minutes sampling windows that are randomly activated over a 12 hour period with at least 30 minutes between windows.

Event Based

Here we activate sensor tracking based on the participant leaving work using a Participant Location trigger.

MetricWire Knowledge Base

Smartphone Sensor Data