3060-1269 Updated statistical methods -part B (06.14.21)

Enhanced Geo-Targeted 3060-1269

Wireless Emergency Alerts June 2021

Part B. Collections of Information Employing Statistical Methods:

1. A description follows:

The respondent universe for the live test is the control group, i.e., employees and other members of the Commission’s alerting partners that elect to participate in the test. The Commission estimates this to be 2,000 individuals spread across three providers (Verizon, AT&T, and T-Mobile), two operating systems (Android and iOS) and four geographic sub-areas within or in proximity of the alerted area, leading to 3 × 2 × 4 = 24 strata.

Sampling estimates for each strata of the control group are provided below:¹

	Potential respondents in universe	Expected response rate	Estimated persons in the sample
Provider 1, Operating System 1, Sub-Area 1	83	100%	83
Provider 2, Operating System 1, Sub-Area 1	83	100%	83
. . .	. . .	. . .	. . .
Provider 3, Operating System 2, Sub-Area 4	83	100%	83
Total:	1992	--	1992

2. The Commission will use a number of procedures for its proposed data collection. Control group respondents can complete the survey directly from their electronic mobile devices. The Commission designed strata along three parameters reflecting areas of potential divergence in performance for WEA. The strata and control group are estimated to encompass three major providers, two major device operating systems and four distinct geographic subareas, leading to 3 × 2 × 4 = 24 strata. The Commission intends to assess (i) the probability of receiving the test message within each target subarea with a 95% confidence interval, and (ii) any large differences in this probability (roughly ±0.05) based on operating system and/or providers at a 0.05 level of significance. These values represent minimal measures of accuracy that the Commission is targeting based on the information collection.

3. The Commission will employ several methods to maximize response rates and deal with potential issues of non-response. First, the Commission will utilize the control group of respondents, described above. The control group consists of employees and other members of the Commission’s alert originator partners and these individuals will be instructed on how to respond to the live test survey, how to opt-in to receive WEA Test alerts on their mobile devices and will be able to participate as part of their normal job duties to their employer. Control group individuals are thus expected to be reliable respondents to the information collection.

The proposed information collection is expected to yield reliable data, both overall and for each stratum described above. Based on the assumptions above and its preliminary statistical modeling, the Commission estimates the accuracy and reliability of the information collected for in each geographic area to be:

• a 95% confidence interval for the probability of receiving the test message in alerted areas with a margin of error ±0.019;

• the ability to detect large differences (roughly ±0.05) in the probability of receiving test messages across operating systems and providers at the 0.05 level of significance.

4. No tests of procedures or methods will be taken in support of this collection.

5. The following individuals have been consulted on statistical aspects of the design:

• Cha-Chi Fan, Mathematical Statistician, Office of Economics and Analytics, Federal Communications Commission, Tel. (202) 418-1554.

• Jay Bennett, Statistician, Public Safety and Homeland Security Bureau, Federal Communications Commission, Tel. (202) 418-2761.

• John Healy, Supervisory Telecommunications Systems Specialist, Public Safety and Homeland Security Bureau, Federal Communications Commission, Tel. (202) 418-2448.

The Information Technology Center of the FCC will actually collect information. The information will be analyzed by the individuals listed above for the Commission.

1 The above reflects 1992 participants, rather than 2,000, due to fractional rounding and the possibility that a small number of respondents may have characteristics that do not fall within one of the 24 strata (e.g., may use an operating system that is neither iOS or Android).

2