Stanford Wockets Activity Project (SWAP)

Frequently Asked Questions (FAQ)

What is a “Wocket”?
A “Wocket” is the name given by engineers at MIT to a custom made activity monitoring unit that consists of a small sensor that detects movement (an accelerometer), a microprocessor that stores data from the motion sensor, a Bluetooth radio that send data from the microprocessor to a mobile phone and a small rechargeable battery.  Wockets are typically worn on the ankle, wrist or hip or carried in the pocket. Click HERE for more information about Wockets.

Why are data sent from the Wockets to the mobile phone?
Body movement data sent by the Wockets to the mobile phone are first stored in the memory in the phone, undergo some processing by computer programs that run on the phone and then data are wirelessly transmitted to a secure server located at MIT. Computer programs running on the server then post a summary of the movement data on a website available to project staff. Also, more detailed data on the server are analyzed by project staff to characterize your activity 24/7. 

What does the green blinking light on the Wocket indicate?
The green blinking light indicates that the Wocket is charged, but not necessarily fully charged. If a Wocket is fully discharged (out of power) no light blinks and it takes about 3 hours for it to fully charge. For more on charging the Wockets click HERE.

Why should I carry the phone with me or keep it in close proximity to me?
The Wockets attempt to send “raw” movement data to the mobile phone once each minute. If you are carrying the phone or if it is near by (within 10 feet or so) these raw data are successfully received by the phone. Raw data are considered high quality data because they provide the best information about your activity type and intensity.

What happens if I am wearing the Wockets but don’t have my phone with me or it is turned off?
If you are wearing the Wockets and you don’t have your phone nearby (or if it is turned off) the microprocessor on the Wocket will average the “raw” data for each minute and then store these “summary data”. Once the Wockets come back in contact with the phone the summary data are sent to the phone and then on to the server. While these summary data are very useful, the raw dataprovide much more detail about your activity. Also, once back in contact with the phone, raw data will be sent by the Wockets to the phone each minute.

How/where do I carry my cell phone?
You should plan to carry the Wocket project phone where it is most convenient for you- pants pocket, jacket pocket, briefcase, backpack, or purse. When at home it can be left on a counter or table in the room where you spend most of your time, on your desk at the office or on the car seat while driving. Data collection should be good for all of these situations.

When should I wear the Wockets?
The Wockets should be worn as much as possible around-the-clock as practical.
It IS OKAY to have them on while washing your hands, washing dishes, washing the car, watering the garden.
It IS OKAY to wear them during exercise in the gym, playing sports.
It IS OKAY to wear Wockets at work as long as they do not cause some risk (discuss any perceived risk with project staff).

When should I not wear the Wockets?
Do NOT wear the Wockets when you take a bath/shower, swimming or surfing. It is highly recommended that the Wockets should NOT GET exposed to too much water (complete submersion). Also, the Wockets should NOT be worn when engaging in contact or collision sports, such as American football or boxing.

Can I wear my Wockets while I am driving?
It IS OKAY to wear the Wockets while driving. The Wockets will not interfere with any of the electronic systems in the vehicle. However, it is required by the driver to follow the California cell phone laws while driving (only hands-free use of your cell phone). For more information on the California cell phone laws see

Can I turn off my cell phone if I am required to (during meetings, theatres, etc.)?
Yes, please follow any such instructions. Remember to turn your phone back on once it is OK to do so. When the phone is turned on the wockets application starts automatically. Just tap on 'Minimize' at the bottom of the Wockets application window and you will be taken to the Home screen. The applicaion will continue running in the background.  Also, remember to continue to wear your Wockets as they will collect data when the phone is off.

Can I take my Wockets on the airplane?
When you take a trip (within the United States) on an airplane we request you take your phone and Wockets with you.  The Wockets should be taken off while going through the security check point at the airport, put safely in your carry-on luggage and then put back on (on wrist or ankle or in pants pocket) after clearing the security checkpoint. The Wockets then can be worn to and while on the plane without additional attention being paid to them. You will need to follow regulations about turning your phone off during the flight. Remember – your Wockets will collect and store data even when your phone is turned off.

When and how long should I charge the Wockets?
You should establish a routine that works for your schedule. It is essential that every evening, at bed time, the phone be plugged into the charger. The wockets need to be charged once every 24-30 hours. To fully re-charge, it takes about 3-4 hours. If you charge you phone at night in the same room you are sleeping it will collect data from the Wockets as well as upload data to the server that has been collected over the past day.

Does it matter on which ankle or wrist, I wear the wockets?
It is preferable that you wear the Wockets on your dominant side. However, if for some reason this creates a problem for you they can be worn on the other wrist or ankle. Please let the staff know if you switch wearing the Wockets to your non-dominant side.

I accidentally put my Wockets in the washing machine. What should I do to dry them out?
Dry them off with a soft cloth and put them in a warm dry place. Switch to the other set of Wockets.

Will the bluetooth of the mobile phone interfere with the Bluetooth connection in my car?
No, the Wocket Bluetooth radio should not interfere with the operation of the Bluetooth connection in your car.

How do I report a lost Wocket or phone?
Call the Stanford Project Team.

Who should I call for technical support?
Denise Shine (phone: 650-725-8538 or email <dshine>) or
Abey Mukkananchery (phone xxx-xxx-xxxx  (
Click HERE to go to the project staff.

What should I do if I don’t want to participate in the study anymore?
Call the Project Director, William Haskell, PhD at 650 725-5012 or any project staff member.Click HERE to contact the project staff.



Footer Links: