This study is now complete. Thank-you to all that participated.
The purpose of this study is to understand how users of constrained computing environments, such as smartphones and cell phones, interact with their devices. Understanding how users interact with their devices is fundamental to the design of systems that utilize periods of non-usage to exchange information with other devices using opportunistic wireless communication.
To participate in this study, you may load a simple application on to your BlackBerry smartphone. This application runs as a background process that records when the device’s screen is turned on or off, and when the device is plugged into a power source for charging. The application is totally non-invasive and will not affect your use of the device. This application contains a graphical component that is accessed by clicking the application’s icon on the BlackBerry Home Screen. Through the graphical component of this application, you may view your usage pattern and upload your usage logs to the study organizer, Earl Oliver, Ph.D. candidate, David R. Cheriton School of Computer Science, University of Waterloo. You may withdraw from the study at any time by revoking your consent to participate in the study, or by removing the application from your device.
Usage logs contain no personal or identifying information. Each log uploaded from this application contains the BlackBerry’s PIN (a number that uniquely identifies each device). This number is used to identify the source of the usage logs, but not the user. We do not maintain a list of participants and their BlackBerry PIN.
This project has been reviewed by, and received ethics clearance though, the Office of Research Ethics at the University of Waterloo. You may contact this office at +1 519-888-4567 ext. 36005 if you have any concerns or questions resulting from your involvement in this study.
How the Smartphone Usage Logger works
This applications consists of a thread that runs as a background process on the BlackBerry that records when the screen is turn on or off and when the device is plugged in for charging. The thread is driven by signals from the BlackBerry OS and therefore does not run continuously in the background draining battery. The user is never aware that the logger is running.
This application contains a graphical component that is accessed by clicking the application’s icon on the BlackBerry Home Screen.
Through the graphical component of this application, you may view your own usage pattern and upload your usage logs to the experiment organizer, Earl Oliver.
The application is totally non-invasive and will not affect your use of the device.
Click here to see more screenshots and more details.
What you get out of this study
control - You may withdrawl from the experiment at anytime by simply uninstalling the Smartphone Usage Logger.
your usage profile - the application illustrates exactly how much and how often you use your smartphone.
transparency - The Smartphone Usage Logger is extremely minimalistic in its use of memory and CPU resources. The application is totally non-invasive and will not affect the participant’s use of their device.
privacy - all data collected from this study is anonymous.
Download
If you are interested in participating in this study, click on the following link to download the application onto your BlackBerry:
Download Smartphone Usage Logger
Source code
The source code for the logging thread can be viewed here.
Results
If you are interested in the results of this study, please join the Tetherless-Interest mailing list.
Removal
When you no longer wish to participate, you can uninstall the Smartphone Usage Logger by going to the Options application on the BlackBerry's home screen.
Then select Advanced Options, then Application.
The logger will be listed as Smartphone Usage Logger. Select the Smartphone Usage Logger entry, and select Delete from the menu.
After confirming the deletion, the Smartphone Usage Logger will be removed from your BlackBerry.
Example smartphone usage pattern
Following is the usage profile for Earl Oliver, as of October 3, 2008.
Weekly device usage distribution
Time using my smartphone
Time between using my smartphone (inactivity)
Device usage duration (seconds):
Min: 0.06
Max: 2152.00
Mean: 54.64
Median: 37.01
Stddev: 76.76
Device inactivity duration (seconds):
Min: 1.00
Max: 35323.00
Mean: 617.46
Median: 140.21
Stddev: 1938.39
Daily device usage (seconds):
Min: 1185.00
Max: 19189.00
Mean: 5916.42
Median: 5151.89
Stddev: 3478.32
Daily usage stats (seconds) by day:
| Day: | Sun | Mon | Tue | Wed | Thu | Fri | Sat |
| Min: | 1798.00 | 1185.00 | 2474.00 | 2416.00 | 2390.00 | 2881.00 | 2725.00 |
| Max: | 10059.00 | 12380.32 | 18759.00 | 19189.00 | 14592.00 | 16294.00 | 15984.00 |
| Mean: | 4864.46 | 4343.14 | 6091.71 | 6372.53 | 5828.96 | 6768.85 | 7187.75 |
| Median: | 4623.00 | 3467.50 | 4603.01 | 5038.12 | 5182.56 | 6353.00 | 6394.50 |
| Stddev: | 2304.50 | 3117.48 | 4076.85 | 4326.30 | 2872.05 | 3119.45 | 3141.41 |
Daily usage occurrences:
Min: 33.00
Max: 258.00
Mean: 109.06
Median: 104.00
Stddev: 41.73
Daily usage occurrences by day:
| Day: | Sun | Mon | Tue | Wed | Thu | Fri | Sat |
| Min: | 43.00 | 33.00 | 55.00 | 66.00 | 64.00 | 75.00 | 77.00 |
| Max: | 177.00 | 208.00 | 177.00 | 258.00 | 239.00 | 154.00 | 199.00 |
| Mean: | 91.44 | 81.50 | 102.39 | 116.11 | 119.12 | 120.35 | 133.67 |
| Median: | 90.50 | 67.00 | 101.00 | 103.00 | 118.00 | 115.00 | 133.50 |
| Stddev: | 33.50 | 49.14 | 30.92 | 44.91 | 40.77 | 26.76 | 35.42 |