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 email: jnelson@hiya.com

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

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: 1. Would you answer this call? 2. Was this call from a trustworthy source? 3. Would you block this number from calling in the future? 4. Why do you think you’re receiving this call?

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

Usability Study: Iconography Three icons against two strings (“Possible Fraud”, “Fake Number”) 400 US participants each Same four questions: 1. Would you answer this call? 2. Was this call from a trustworthy source? 3. Would you block this number from calling in the future? 4. Why do you think you’re receiving this call?

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

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