1. ATIS/SIP Forum IP NNI Task Force Tyson's Corner, VA November 7-8, 2017
Contribution
TITLE: Contribution on Display Guidelines
SOURCE: Jonathan Nelson (Hiya)
_______________________________
Abstract
This presentation aims to progress discussion on the display guidelines with usability results from string and iconography testing conducted by Hiya.
NOTICE
This contribution has been prepared to assist the ATIS PTSC. This document is offered to the Committee as a basis for discussion and is not a binding agreement on Ericsson or any other company. The requirements are subject to change in form and numerical value after more study. Ericsson specifically reserves the right to add to, or withdraw, the statements contained
CONTACT: Jonathan Nelson

2. Latest Usability Study Measurements Latest Usability Study Goals
Measure impact of warnings on caller trust, pickup rates, and block rates
Compare impacts of “informative” strings vs. “cautionary” strings
Test consumer awareness of “Spoof” term, or concept in general
Experiment with a few specific common string and icon ideas
Conducted in October 2017, US participants via Mechanical Turk
Latest Usability Study Goals
Determine options to increase user caution
Determine if caution can increase without increasing block rates
Find recommended strings and icons for UE display

3. Usability Study: Caller ID Strings
Seven different display versions
Default (phone number only)
“Private Number” (no phone number)
“Fake Phone Number”
“Possible Fraud”
“Unknown Caller”
“Caller Not Verified”
“Spoofed Number”
400 participants each (no overlap) asked four questions:
Would you answer this call?
Was this call from a trustworthy source?
Would you block this number from calling in the future?
Why do you think you’re receiving this call?

4. Usability Study: Caller ID Strings
Default 30% pickup rate and 29% block rate; compared from this result
Similar results between “spoofed” and “fake”
Strongest reaction with “Possible Fraud”
Persistent connection between trust and block
“Ratio” shows block increase vs. trust decrease

5. Usability Study: Iconography
Three icons against two strings (“Possible Fraud”, “Fake Number”)
400 US participants each
Same four questions:
Would you answer this call?
Was this call from a trustworthy source?
Would you block this number from calling in the future?
Why do you think you’re receiving this call?

6. Usability Study: Iconography
Icons have lesser additional impact with text
Icons can boost reaction to weaker strings, or vice versa
Icons generally cause more user caution with less additional blocking

7. Summary/Conclusions
No surprise that warning strings create stronger reactions than informative strings
It may not be possible to isolate consumer warning from block behavior
Block behavior from study needs real-world experimentation
Icon optional, can be used to “strengthen” a string if is an option
Recommendation:
“Fake Number” string to inform user as CNAM-compatible warning; include stop sign icon if possible to boost user caution with negligible block rate change; target user education re: blocking