Gap Sense
For use under the guidance of an Orientation and Mobility Specialist. It does not replace O&M instruction.
Your phone volume is low. Press the volume up button on the side of the phone.
Using example times. Your instructor sets your real crossing times in Instructor setup or by sending you a link.
Start here
Your O&M Specialist measures your crossing times and sets them. Open the link your instructor sent, or enter the times in Instructor setup.
Crossing times not set
Your instructor has not turned on any activities yet.
Develop an accurate sense of your crossing times through practice and feedback.
Using example times. Your instructor sets your real crossing times.
Practice mode
Times needed
Enter both crossing times in Instructor setup before practicing.
Get ready to compare your time to various sample times. Press Ready. When the sound starts, it is like hearing a vehicle. Stop it when you think you would finish crossing.
The app plays a sample warning time: the time from first detecting a vehicle until it passes in front of you. Is it longer, shorter, or about the same as your crossing time?
Longer does not mean long enough
A warning time that is longer than your crossing time is not, by itself, enough to cross. Work with your Orientation and Mobility Specialist on how many vehicles to sample, how to judge if a warning time is long enough, and all the other skills involved in crossing streets without traffic control.
Position yourself as directed by your O&M Specialist, so you can look or listen for approaching vehicles. Swipe left or right the moment you think you detect (see or hear) a vehicle, in the direction it is coming from. Then tap when it passes in front of you.
Longer does not mean long enough
A warning time that is longer than your crossing time is not, by itself, enough to cross. Work with your Orientation and Mobility Specialist on how many vehicles to sample, how to judge if a warning time is long enough, and all the other skills involved in crossing streets without traffic control.
Send to my instructor
Nothing is ever sent automatically. You see the report first, then choose how to send it: Messages, Mail, or any other app. It carries your student code, never your name.
My data
Everything stays on this device. Deleting is permanent.
Use with your O&M Specialist
Gap Sense is meant to be used under the guidance of an Orientation and Mobility Specialist. It is not a replacement for instruction and does not cover all the skills needed to cross streets.
Sounds
Every sound means something. Play them here any time.
For students
VoiceOver: the swipe areas in the iPhone app are direct touch areas. Turn on Direct Touch for Gap Sense once (VoiceOver rotor, Direct Touch), and swipes and taps there work the same as with VoiceOver off. The buttons are still there if you prefer them.
- Your crossing times come from your O&M Specialist. They time you crossing and set the times in Instructor setup, or send you a link that sets them.
- 1. Practice my timing. Tap Begin, then tap again when you think you would have arrived. You hear the difference rather than being told a number.
- 2. Comparison preparation. Press Ready. When the sound starts, stop it when you think your crossing time is up.
- 3. Comparison practice. The app plays a sample warning time. Decide whether it was longer, shorter, or about the same as your crossing time, then feel the difference.
- 4. At the street. The same judgment with real vehicles.
Never count. The point is to feel the length of time, not to measure it.
For instructors
- Setting up. Time at least three crossings and use the longest. Enter the first-half and full-street times in Instructor setup. There you also choose which activities and options the student sees, then send everything to the student's phone as one link.
- Margin of error. You choose and set it. The app defaults to 0.40 seconds; 0.50 seconds has historically been taught with a stopwatch. There is no research yet on the right value.
- Directions. A vehicle approaching from the left is compared with the first-half time; from the right, with the full-street time.
- Feedback modes. Audio, visual, or both, under Accessibility. Visual-only supports Deaf students; vibration supports DeafBlind students in the installed app.
- Progress. The student can show you the Progress screen, or send you a written report. Data never leaves their device unless they send it.
- Experimental. The adaptive margin is off by default and unproven; turn it on in Instructor setup only to try it.
About
Gap Sense
Free, open source, and private. Nothing leaves this device unless you send it.
For the O&M Specialist. Set the crossing times, choose what the student can see and change, then send it all to the student's phone as one link.
Instructor code
Crossing times
Measured and set by the O&M Specialist. Time at least three crossings and use the longest.
Chosen and set by the instructor. 0.50 seconds has historically been taught; there is no research yet on the right value.
Activities the student sees
Practice my timing
Which practice modes the student can choose.
Comparison preparation
Comparison practice
Only offered after a correct "longer" or "shorter" answer.
Combined: a steady sound for the crossing time, the right or wrong sound where the sample ended, then the student's sound at their estimate. Like Practice my timing: the student's sounds against the real difference.
At the street
Difficulty Experimental
Off by default; the instructor decides. When on, each task and street keeps its own margin. It tightens slowly while accuracy stays high and goes straight back to the set margin when accuracy drops. It never goes easier than the margin above, and never below 0.10 seconds. The research on the right pace is not settled.
Instructor and student
Links and reports travel by ordinary text or email, so they carry this code and never a name. Use a code that cannot be linked to the person.
Send this setup to the student
Makes one link that sets up the student's phone. Choose what it carries.
The student taps the link once. If the app is installed, they then choose "Open in the Gap Sense app".
Instructor code (optional)
Set a code so the student cannot change these settings. Leave empty for no code.
Open an activity with Siri
These work without any setup. Say "Hey Siri", then one of these:
- "Practice my timing in Gap Sense"
- "Comparison preparation in Gap Sense"
- "Comparison practice in Gap Sense"
- "At the street in Gap Sense"
To use your own words, open the Shortcuts app, choose Gap Sense, and add any of the four to a shortcut with the name you want.
App shortcuts
Touch and hold the Gap Sense icon on your home screen to open any of the four activities directly. Drag one onto your home screen to keep it there.
With Google Assistant, say "Open Gap Sense".
Shortcuts
Siri and app shortcuts work in the installed iPhone and Android apps. In a browser, add this page to your home screen to open it in one tap.