B. Collections of Information Employing Statistical Methods.
When Item 17 on the Form OMB 83-I is checked “Yes”, the following documentation should be included in the Supporting Statement to the extent it applies to the methods proposed:
1. Describe (including numerical estimate) the potential respondent universe and any sampling or other respondent selection method to be used. Data on the number of entities (e.g., establishments, State and local government units, households, or persons) in the universe covered by the collection and in the corresponding sample are to be provided in tabular form for the universe as a whole and for each of the strata in the proposed sample. Indicate expected response rates for the collection as a whole. If the collection has been conducted previously, include the actual response rate achieved during the last collection.
Federal Emergency Management Agency (FEMA) Individual and Community Preparedness Division (ICPD) will collect preparedness information from the public via a telephone survey. This collection of information, which began in 2007, is necessary to increase the effectiveness of awareness and recruitment campaigns, messaging and public information, community outreach efforts, and strategic planning initiatives. The household telephone survey will measure public’s knowledge, attitudes, and behaviors relative to preparing for of the following hazards: Tornado, Hurricane, Flood, Earthquakes, Wildfire, Terrorism, Extreme Winter weather, Hazardous materials and Pandemic Flu.
The potential respondent pool includes the entire civilian non-institutionalized U.S. adult population residing in telephone-equipped dwellings or owning a cell phone. This population does not include adults in penal, mental, or other institutions; adults living in dormitories, barracks, or boarding houses; adults living in a dwelling without a telephone; and/or adults who do not speak English or Spanish well enough to be interviewed.
The survey will be conducted twice every year, and this approval period will cover 3 years. The total number of respondents will be 3,000 adults per administration and so it will be 6,000 per year. The total number of respondents (3,000) for any particular administration will include a national level sample of about 1,000 respondents and four separate oversamples (of size 500 each) for four hazard specific areas. The hazard specific areas will be defined in terms of complete counties (or fipscodes). The selection of the hazard profiles to be surveyed in any specific administration will vary across different administrations of the survey. Hazards selected for the 2014 surveys are Flood, Hurricane, Tornado, Wildfire, Earthquake and Winter Storm and Extreme Cold. In each administration, four hazard areas will be surveyed while each of these hazards will be covered in one or both administrations.
The telephone samples will include both landline and cell phones to minimize bias in survey based estimates. In each administration, seven independent telephone samples will be chosen to generate the targeted number of surveys for the national and for each of the six hazard areas. For each sample, the selection of landline numbers will be based on list-assisted RDD (Random Digit Dialing) sampling of telephone numbers for the corresponding geographic area. The cell phone sample will be a simple random sample drawn from all dedicated exchanges for cell phones for the targeted areas. For respondents reached on a landline phone, one respondent will be chosen at random from all eligible adults within a sampled household. For respondents reached on a cell phone, the person answering the call will be selected as the respondent if he or she is otherwise found eligible.
The goal will be to maximize the response rate by taking necessary steps as outlined later in this document on “Methods to maximize response rates.” The calculation of response rates will be based on AAPOR RR3 definition.
2. Describe the procedures for the collection of information including:
-Statistical methodology for stratification and sample selection:
In each administration of the telephone survey, about 1,000 interviews nationwide and 500 interviews for each of the four selected hazard areas will be completed. Samples will be independently drawn for the national and for each of the hazard profile areas defined based on complete counties. In order to minimize bias, both landline and cell phones will be included in the all telephone samples.
For the National sample, the target population will be geographically stratified into four census regions (Northeast, Midwest, South, and West) and sampling will be done independently within each stratum (region). The definition of the four census regions in terms of states is given below.
Northeast: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont, New Jersey, New York, and Pennsylvania.
Midwest: Illinois, Indiana, Michigan, Ohio, Wisconsin, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, and South Dakota.
South: Delaware, District of Columbia, Florida, Georgia, Maryland, North Carolina, South Carolina, Virginia, West Virginia, Alabama, Kentucky, Mississippi, Tennessee, Arkansas, Louisiana, Oklahoma, and Texas.
West: Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Utah, Wyoming, Alaska, California, Hawaii, Oregon, and Washington.
The sample allocation across the four census regions (Northeast, Midwest, South and West) will be based on proportional allocation i.e. the sample size allocated to any particular region will be roughly in proportion to the size of that region in terms of the estimated number of adults. Using proportional sample allocation, the targeted number of surveys to be completed in each region is expected to be close to those proportions. Within each region, roughly 50 percent of the interviews will be done from the cell phone sample while the rest (50%) will be done from the landline sample. It may be noted that the actual number of completed surveys for each census region (and by landline and cell phone strata within each region) will depend on observed response rates and so they may not exactly match the corresponding targets. However, the goal will be to meet those targets to the extent possible by constant monitoring of the response rates and by optimally releasing the sample in a sequential manner throughout the data collection period.
Within each region, the sampling of landline and cell phones will be carried out separately from the respective sampling frames. The landline RDD (Random Digit Dialing) sample of telephone numbers will be selected (without replacement) following the list-assisted telephone sampling method. For within-household sampling, the contractor will use the “most recent birthday” method to randomly select one eligible person from all eligible adults in each sampled household. Following the “most recent birthday” method, the interviewer asks to speak with the eligible person in the household who most recently had a birthday. This is much less intrusive than the purely random selection method or grid selection that requires enumeration of all household members to make a respondent selection.
The cell phone sample of telephone numbers will be drawn (without replacement) separately from the corresponding dedicated (to cell phones) telephone exchanges. For respondents reached on cell phones, there will not be any additional stage of sampling (as there is with the within-household sampling for landline sample). The person answering the call will be selected for the survey if he/she is found otherwise eligible. For both landline and cell phones, the geographic location of the respondent will be determined based on respondent’s self-reported response to a question on location (like “what is your zip-code?” and what is your county?). Data will be collected from all respondents regardless of whether they have access to a landline, a cell phone or both. Respondents will be asked a series of questions to gather information on his/her use of telephone (cell only, landline only, or dual-user cell mostly and other dual users).
As mentioned above, the cell phone numbers will be sampled from the telephone exchanges dedicated to cell phones while the landline numbers will be sampled from all area code exchange combinations for the corresponding geographic area. It may be noted that due to continuous porting of numbers from landline to cell and cell to landline, some numbers from landline exchanges may turn out to be cell phones and conversely, some numbers sampled from the cell phone exchanges may actually be landline numbers. However, such numbers will be relatively rare and the vast majority of landline and cell phone numbers will be from the corresponding frames. The survey will also find out from the respondents if the number called is actually a landline or a cell phone number. It is also possible that an individual respondent may have a telephone number in one region while he/she may actually be living in another region. The physical location of respondents will therefore be based on their self-reported location information (for example, based on their self-reported zip-code or county information) and will not be determined based on their telephone exchange.
The hazard area samples, as mentioned before, will be selected independently following procedures similar to those used for the national sample described above. The target population for each hazard area survey will consist of groups of counties identified based on specific requirements for each hazard. The counties (fips) identified for each hazard are presented in Table 1 through Table 6 below.
Table 1: Counties identified for Hazard - Flood
County |
State |
FIPS |
Jefferson |
AL |
1073 |
Coffee |
AL |
1031 |
Columbia |
AR |
5027 |
Napa |
CA |
6055 |
Marin |
CA |
6041 |
Sonoma |
CA |
6097 |
Monterey |
CA |
6053 |
San Luis Obisp |
CA |
6079 |
Larimer |
CO |
8069 |
Jefferson |
CO |
8059 |
Miami-Dade |
FL |
12086 |
Broward |
FL |
12011 |
*Dade |
FL |
12025 |
Linn |
IA |
19113 |
Wayne |
IA |
19185 |
Johnson |
IA |
19103 |
Marshall |
IA |
19127 |
Cook |
IL |
17031 |
Bartholomew |
IN |
18005 |
Morgan |
IN |
18109 |
Polk |
MN |
27119 |
Roseau |
MN |
27135 |
Franklin |
MO |
29071 |
Grand Forks |
ND |
38035 |
Cass |
ND |
38017 |
Somerset |
NJ |
34035 |
Sussex |
NJ |
34037 |
Washoe |
NV |
32031 |
Delaware |
NY |
36025 |
Broome |
NY |
36007 |
Sullivan |
NY |
36105 |
Tioga |
NY |
36107 |
Lake |
OH |
39085 |
Summit |
OH |
39153 |
Luzerne |
PA |
42079 |
Susquehanna |
PA |
42115 |
Jefferson |
PA |
42065 |
Davidson |
TN |
47037 |
Gibson |
TN |
47053 |
El Paso |
TX |
48141 |
Burnet |
TX |
48053 |
Washington |
UT |
49053 |
Green |
WI |
55045 |
Jefferson |
WI |
55055 |
Table 2: Counties identified for Hazard - Hurricane
County |
State |
FIPS |
Mobile |
AL |
1097 |
Baldwin |
AL |
1003 |
Choctaw |
AL |
1023 |
Washington |
AL |
1129 |
Butler |
AL |
1013 |
Clarke |
AL |
1025 |
Conecuh |
AL |
1035 |
Covington |
AL |
1039 |
Crenshaw |
AL |
1041 |
Escambia |
AL |
1053 |
Monroe |
AL |
1099 |
Wilcox |
AL |
1131 |
Broward |
FL |
12011 |
Collier |
FL |
12021 |
Miami-Dade |
FL |
12086 |
Palm Beach |
FL |
12099 |
Escambia |
FL |
12033 |
Okaloosa |
FL |
12091 |
Santa Rosa |
FL |
12113 |
Charlotte |
FL |
12015 |
DeSoto |
FL |
12027 |
Lee |
FL |
12071 |
Manatee |
FL |
12081 |
Sarasota |
FL |
12115 |
Brevard |
FL |
12009 |
Indian River |
FL |
12061 |
Marion |
FL |
12083 |
St. Lucie |
FL |
12111 |
Volusia |
FL |
12127 |
Hardee |
FL |
12049 |
Highlands |
FL |
12055 |
Polk |
FL |
12105 |
*Dade |
FL |
12025 |
Monroe |
FL |
12087 |
Glades |
FL |
12043 |
Hendry |
FL |
12051 |
Kauai |
HI |
15007 |
Orleans |
LA |
22071 |
St. Bernard |
LA |
22087 |
Jefferson |
LA |
22051 |
St. Tammany |
LA |
22103 |
East Baton Rou |
LA |
22033 |
Plaquemines |
LA |
22075 |
Lafourche |
LA |
22057 |
Tangipahoa |
LA |
22105 |
Washington |
LA |
22117 |
St. John the B |
LA |
22095 |
Pointe Coupee |
LA |
22077 |
West Feliciana |
LA |
22125 |
East Feliciana |
LA |
22037 |
St. Helena |
LA |
22091 |
Iberville |
LA |
22047 |
West Baton Rou |
LA |
22121 |
Ascension |
LA |
22005 |
Livingston |
LA |
22063 |
Assumption |
LA |
22007 |
St. James |
LA |
22093 |
St. Charles |
LA |
22089 |
Terrebonne |
LA |
22109 |
Cameron |
LA |
22023 |
Vernon |
LA |
22115 |
Rapides |
LA |
22079 |
Avoyelles |
LA |
22009 |
Beauregard |
LA |
22011 |
Allen |
LA |
22003 |
Evangeline |
LA |
22039 |
St. Landry |
LA |
22097 |
Calcasieu |
LA |
22019 |
Jefferson Davi |
LA |
22053 |
Acadia |
LA |
22001 |
Lafayette |
LA |
22055 |
St. Martin |
LA |
22099 |
Vermilion |
LA |
22113 |
Iberia |
LA |
22045 |
St. Mary |
LA |
22101 |
Harrison |
MS |
28047 |
Hancock |
MS |
28045 |
Jackson |
MS |
28059 |
Pearl River |
MS |
28109 |
Wilkinson |
MS |
28157 |
Amite |
MS |
28005 |
Pike |
MS |
28113 |
Walthall |
MS |
28147 |
Jones |
MS |
28067 |
Leake |
MS |
28079 |
Warren |
MS |
28149 |
Hinds |
MS |
28049 |
Lauderdale |
MS |
28075 |
Simpson |
MS |
28127 |
Lamar |
MS |
28073 |
Forrest |
MS |
28035 |
Bolivar |
MS |
28011 |
Sunflower |
MS |
28133 |
Leflore |
MS |
28083 |
Grenada |
MS |
28043 |
Carroll |
MS |
28015 |
Montgomery |
MS |
28097 |
Webster |
MS |
28155 |
Clay |
MS |
28025 |
Lowndes |
MS |
28087 |
Choctaw |
MS |
28019 |
Oktibbeha |
MS |
28105 |
Washington |
MS |
28151 |
Humphreys |
MS |
28053 |
Holmes |
MS |
28051 |
Attala |
MS |
28007 |
Winston |
MS |
28159 |
Noxubee |
MS |
28103 |
Issaquena |
MS |
28055 |
Sharkey |
MS |
28125 |
Yazoo |
MS |
28163 |
Madison |
MS |
28089 |
Neshoba |
MS |
28099 |
Kemper |
MS |
28069 |
Rankin |
MS |
28121 |
Scott |
MS |
28123 |
Newton |
MS |
28101 |
Claiborne |
MS |
28021 |
Copiah |
MS |
28029 |
Smith |
MS |
28129 |
Jasper |
MS |
28061 |
Clarke |
MS |
28023 |
Jefferson |
MS |
28063 |
Adams |
MS |
28001 |
Franklin |
MS |
28037 |
Lincoln |
MS |
28085 |
Lawrence |
MS |
28077 |
Jefferson Davi |
MS |
28065 |
Covington |
MS |
28031 |
Marion |
MS |
28091 |
Onslow |
NC |
37133 |
Pender |
NC |
37141 |
New Hanover |
NC |
37129 |
Yadkin |
NC |
37197 |
Wilson |
NC |
37195 |
Charleston |
SC |
45019 |
Georgetown |
SC |
45043 |
Horry |
SC |
45051 |
Dorchester |
SC |
45035 |
York |
SC |
45091 |
Sumter |
SC |
45085 |
Berkeley |
SC |
45015 |
Williamsburg |
SC |
45089 |
Jasper |
TX |
48241 |
Tyler |
TX |
48457 |
Newton |
TX |
48351 |
Hardin |
TX |
48199 |
Jefferson |
TX |
48245 |
Orange |
TX |
48361 |
Brazoria |
TX |
48039 |
Chambers |
TX |
48071 |
Fort Bend |
TX |
48157 |
Galveston |
TX |
48167 |
Grimes |
TX |
48185 |
Harris |
TX |
48201 |
Houston |
TX |
48225 |
Liberty |
TX |
48291 |
Montgomery |
TX |
48339 |
Polk |
TX |
48373 |
San Jacinto |
TX |
48407 |
Trinity |
TX |
48455 |
Walker |
TX |
48471 |
Waller |
TX |
48473 |
Washington |
TX |
48477 |
Matagorda |
TX |
48321 |
Table 3: Counties identified for Hazard - Tornado
County |
State |
FIPS |
Tuscaloosa |
AL |
1125 |
Limestone |
AL |
1083 |
Jefferson |
AL |
1073 |
Coffee |
AL |
1031 |
St. Clair |
AL |
1115 |
Marion |
AL |
1093 |
Calhoun |
AL |
1015 |
Walker |
AL |
1127 |
Tallapoosa |
AL |
1123 |
Van Buren |
AR |
5141 |
Sebastian |
AR |
5131 |
Crawford |
AR |
5033 |
Polk |
AR |
5113 |
Pulaski |
AR |
5119 |
*Dade |
FL |
12025 |
Grant |
KS |
20067 |
Kiowa |
KS |
20097 |
Sedgwick |
KS |
20173 |
Bullitt |
KY |
21029 |
Hampden |
MA |
25013 |
Charles |
MD |
24017 |
Prince George' |
MD |
24033 |
Genesee |
MI |
26049 |
Branch |
MI |
26023 |
Hillsdale |
MI |
26059 |
Lenawee |
MI |
26091 |
Monroe |
MI |
26115 |
Hennepin |
MN |
27053 |
Nicollet |
MN |
27103 |
Jasper |
MO |
29097 |
Lawrence |
MS |
28077 |
Yazoo |
MS |
28163 |
Wake |
NC |
37183 |
Cumberland |
NC |
37051 |
Lancaster |
NE |
31109 |
Wood |
OH |
39173 |
Oklahoma |
OK |
40109 |
Cleveland |
OK |
40027 |
Washita |
OK |
40149 |
Rutherford |
TN |
47149 |
Davidson |
TN |
47037 |
McLennan |
TX |
48309 |
Wichita |
TX |
48485 |
Bowie |
TX |
48037 |
Salt Lake |
UT |
49035 |
Table 4: Counties identified for Hazard - Earthquake
FIPS |
County |
State |
15001 |
Hawaii County |
Hawaii |
02013 |
Aleutians East Borough |
Alaska |
02016 |
Aleutians West Census Area |
Alaska |
02020 |
Anchorage Municipality |
Alaska |
02060 |
Bristol Bay Borough |
Alaska |
02068 |
Denali Borough |
Alaska |
02090 |
Fairbanks North Star Borough |
Alaska |
02100 |
Haines Borough |
Alaska |
02105 |
Hoonah-Angoon Census Area |
Alaska |
02122 |
Kenai Peninsula Borough |
Alaska |
02150 |
Kodiak Island Borough |
Alaska |
02164 |
Lake and Peninsula Borough |
Alaska |
02170 |
Matanuska-Susitna Borough |
Alaska |
02220 |
Sitka City and Borough |
Alaska |
02261 |
Valdez-Cordova Census Area |
Alaska |
02282 |
Yakutat City and Borough |
Alaska |
05021 |
Clay County |
Arkansas |
05031 |
Craighead County |
Arkansas |
05035 |
Crittenden County |
Arkansas |
05055 |
Greene County |
Arkansas |
05093 |
Mississippi County |
Arkansas |
05111 |
Poinsett County |
Arkansas |
06001 |
Alameda County |
California |
06003 |
Alpine County |
California |
06011 |
Colusa County |
California |
06013 |
Contra Costa County |
California |
06015 |
Del Norte County |
California |
06019 |
Fresno County |
California |
06021 |
Glenn County |
California |
06023 |
Humboldt County |
California |
06025 |
Imperial County |
California |
06027 |
Inyo County |
California |
06029 |
Kern County |
California |
06031 |
Kings County |
California |
06033 |
Lake County |
California |
06037 |
Los Angeles County |
California |
06041 |
Marin County |
California |
06045 |
Mendocino County |
California |
06047 |
Merced County |
California |
06051 |
Mono County |
California |
06053 |
Monterey County |
California |
06055 |
Napa County |
California |
06059 |
Orange County |
California |
06063 |
Plumas County |
California |
06065 |
Riverside County |
California |
06069 |
San Benito County |
California |
06071 |
San Bernardino County |
California |
06073 |
San Diego County |
California |
06075 |
San Francisco County |
California |
06079 |
San Luis Obispo County |
California |
06081 |
San Mateo County |
California |
06083 |
Santa Barbara County |
California |
06085 |
Santa Clara County |
California |
06087 |
Santa Cruz County |
California |
06091 |
Sierra County |
California |
06095 |
Solano County |
California |
06097 |
Sonoma County |
California |
06099 |
Stanislaus County |
California |
06105 |
Trinity County |
California |
06111 |
Ventura County |
California |
06113 |
Yolo County |
California |
15005 |
Kalawao County |
Hawaii |
15009 |
Maui County |
Hawaii |
17003 |
Alexander County |
Illinois |
17087 |
Johnson County |
Illinois |
17127 |
Massac County |
Illinois |
17153 |
Pulaski County |
Illinois |
17181 |
Union County |
Illinois |
21007 |
Ballard County |
Kentucky |
21039 |
Carlisle County |
Kentucky |
21075 |
Fulton County |
Kentucky |
21083 |
Graves County |
Kentucky |
21105 |
Hickman County |
Kentucky |
21145 |
McCracken County |
Kentucky |
29023 |
Butler County |
Missouri |
29031 |
Cape Girardeau County |
Missouri |
29069 |
Dunklin County |
Missouri |
29133 |
Mississippi County |
Missouri |
29143 |
New Madrid County |
Missouri |
29155 |
Pemiscot County |
Missouri |
29201 |
Scott County |
Missouri |
29207 |
Stoddard County |
Missouri |
32005 |
Douglas County |
Nevada |
32009 |
Esmeralda County |
Nevada |
32019 |
Lyon County |
Nevada |
32021 |
Mineral County |
Nevada |
32029 |
Storey County |
Nevada |
32510 |
Carson City |
Nevada |
41011 |
Coos County |
Oregon |
41015 |
Curry County |
Oregon |
41041 |
Lincoln County |
Oregon |
45015 |
Berkeley County |
South Carolina |
45035 |
Dorchester County |
South Carolina |
47033 |
Crockett County |
Tennessee |
47045 |
Dyer County |
Tennessee |
47053 |
Gibson County |
Tennessee |
47075 |
Haywood County |
Tennessee |
47095 |
Lake County |
Tennessee |
47097 |
Lauderdale County |
Tennessee |
47131 |
Obion County |
Tennessee |
47167 |
Tipton County |
Tennessee |
47183 |
Weakley County |
Tennessee |
53009 |
Clallam County |
Washington |
53027 |
Grays Harbor County |
Washington |
53029 |
Island County |
Washington |
53031 |
Jefferson County |
Washington |
53033 |
King County |
Washington |
53035 |
Kitsap County |
Washington |
53041 |
Lewis County |
Washington |
53045 |
Mason County |
Washington |
53049 |
Pacific County |
Washington |
53053 |
Pierce County |
Washington |
53055 |
San Juan County |
Washington |
53061 |
Snohomish County |
Washington |
53067 |
Thurston County |
Washington |
56039 |
Teton County |
Wyoming |
Table 5: Counties identified for Hazard - Wildfire
FIPS |
County |
State |
01003 |
Baldwin County |
Alabama |
01097 |
Mobile County |
Alabama |
04013 |
Maricopa County |
Arizona |
04019 |
Pima County |
Arizona |
06007 |
Butte County |
California |
06019 |
Fresno County |
California |
06029 |
Kern County |
California |
06037 |
Los Angeles County |
California |
06053 |
Monterey County |
California |
06059 |
Orange County |
California |
06061 |
Placer County |
California |
06065 |
Riverside County |
California |
06071 |
San Bernardino County |
California |
06073 |
San Diego County |
California |
06083 |
Santa Barbara County |
California |
06085 |
Santa Clara County |
California |
06113 |
Yolo County |
California |
08013 |
Boulder County |
Colorado |
08041 |
El Paso County |
Colorado |
08069 |
Larimer County |
Colorado |
12001 |
Alachua County |
Florida |
12005 |
Bay County |
Florida |
12009 |
Brevard County |
Florida |
12011 |
Broward County |
Florida |
12015 |
Charlotte County |
Florida |
12017 |
Citrus County |
Florida |
12019 |
Clay County |
Florida |
12021 |
Collier County |
Florida |
12031 |
Duval County |
Florida |
12035 |
Flagler County |
Florida |
12053 |
Hernando County |
Florida |
12057 |
Hillsborough County |
Florida |
12061 |
Indian River County |
Florida |
12069 |
Lake County |
Florida |
12071 |
Lee County |
Florida |
12083 |
Marion County |
Florida |
12085 |
Martin County |
Florida |
12086 |
Miami-Dade County |
Florida |
12091 |
Okaloosa County |
Florida |
12095 |
Orange County |
Florida |
12097 |
Osceola County |
Florida |
12099 |
Palm Beach County |
Florida |
12101 |
Pasco County |
Florida |
12105 |
Polk County |
Florida |
12107 |
Putnam County |
Florida |
12109 |
St. Johns County |
Florida |
12113 |
Santa Rosa County |
Florida |
12115 |
Sarasota County |
Florida |
12127 |
Volusia County |
Florida |
13187 |
Lumpkin County |
Georgia |
15009 |
Maui County |
Hawaii |
16001 |
Ada County |
Idaho |
20103 |
Leavenworth County |
Kansas |
20161 |
Riley County |
Kansas |
22103 |
St. Tammany Parish |
Louisiana |
28047 |
Harrison County |
Mississippi |
28059 |
Jackson County |
Mississippi |
32003 |
Clark County |
Nevada |
34005 |
Burlington County |
New Jersey |
34029 |
Ocean County |
New Jersey |
35001 |
Bernalillo County |
New Mexico |
45015 |
Berkeley County |
South Carolina |
48027 |
Bell County |
Texas |
48135 |
Ector County |
Texas |
48139 |
Ellis County |
Texas |
48181 |
Grayson County |
Texas |
48187 |
Guadalupe County |
Texas |
48303 |
Lubbock County |
Texas |
48329 |
Midland County |
Texas |
48355 |
Nueces County |
Texas |
48367 |
Parker County |
Texas |
48375 |
Potter County |
Texas |
48381 |
Randall County |
Texas |
48439 |
Tarrant County |
Texas |
48441 |
Taylor County |
Texas |
48485 |
Wichita County |
Texas |
49011 |
Davis County |
Utah |
49049 |
Utah County |
Utah |
49057 |
Weber County |
Utah |
53005 |
Benton County |
Washington |
53063 |
Spokane County |
Washington |
54039 |
Kanawha County |
West Virginia |
54081 |
Raleigh County |
West Virginia |
Table 6: Counties identified for Hazard – Winter Storm and Extreme Cold
FIPS |
County |
State |
02180 |
Nome Census Area |
Alaska |
02185 |
North Slope Borough |
Alaska |
02188 |
Northwest Arctic Borough |
Alaska |
02261 |
Valdez-Cordova Census Area |
Alaska |
02290 |
Yukon-Koyukuk Census Area |
Alaska |
04005 |
Coconino County |
Arizona |
04017 |
Navajo County |
Arizona |
04021 |
Pinal County |
Arizona |
06071 |
San Bernardino County |
California |
06093 |
Siskiyou County |
California |
06103 |
Tehama County |
California |
06107 |
Tulare County |
California |
06109 |
Tuolumne County |
California |
08035 |
Douglas County |
Colorado |
08059 |
Jefferson County |
Colorado |
08077 |
Mesa County |
Colorado |
08085 |
Montrose County |
Colorado |
08097 |
Pitkin County |
Colorado |
08103 |
Rio Blanco County |
Colorado |
08107 |
Routt County |
Colorado |
08113 |
San Miguel County |
Colorado |
08123 |
Weld County |
Colorado |
09001 |
Fairfield County |
Connecticut |
09005 |
Litchfield County |
Connecticut |
09009 |
New Haven County |
Connecticut |
10001 |
Kent County |
Delaware |
10003 |
New Castle County |
Delaware |
10005 |
Sussex County |
Delaware |
13241 |
Rabun County |
Georgia |
16013 |
Blaine County |
Idaho |
16029 |
Caribou County |
Idaho |
16037 |
Custer County |
Idaho |
16055 |
Kootenai County |
Idaho |
16059 |
Lemhi County |
Idaho |
16077 |
Power County |
Idaho |
16081 |
Teton County |
Idaho |
16087 |
Washington County |
Idaho |
17011 |
Bureau County |
Illinois |
17067 |
Hancock County |
Illinois |
17071 |
Henderson County |
Illinois |
17109 |
McDonough County |
Illinois |
17131 |
Mercer County |
Illinois |
17155 |
Putnam County |
Illinois |
17187 |
Warren County |
Illinois |
19011 |
Benton County |
Iowa |
19019 |
Buchanan County |
Iowa |
19031 |
Cedar County |
Iowa |
19045 |
Clinton County |
Iowa |
19055 |
Delaware County |
Iowa |
19057 |
Des Moines County |
Iowa |
19061 |
Dubuque County |
Iowa |
19087 |
Henry County |
Iowa |
19095 |
Iowa County |
Iowa |
19097 |
Jackson County |
Iowa |
19101 |
Jefferson County |
Iowa |
19103 |
Johnson County |
Iowa |
19105 |
Jones County |
Iowa |
19107 |
Keokuk County |
Iowa |
19111 |
Lee County |
Iowa |
19113 |
Linn County |
Iowa |
19115 |
Louisa County |
Iowa |
19119 |
Lyon County |
Iowa |
19139 |
Muscatine County |
Iowa |
19143 |
Osceola County |
Iowa |
19163 |
Scott County |
Iowa |
19177 |
Van Buren County |
Iowa |
19183 |
Washington County |
Iowa |
23001 |
Androscoggin County |
Maine |
23003 |
Aroostook County |
Maine |
23005 |
Cumberland County |
Maine |
23007 |
Franklin County |
Maine |
23009 |
Hancock County |
Maine |
23011 |
Kennebec County |
Maine |
23013 |
Knox County |
Maine |
23015 |
Lincoln County |
Maine |
23017 |
Oxford County |
Maine |
23019 |
Penobscot County |
Maine |
23021 |
Piscataquis County |
Maine |
23023 |
Sagadahoc County |
Maine |
23025 |
Somerset County |
Maine |
23027 |
Waldo County |
Maine |
23029 |
Washington County |
Maine |
23031 |
York County |
Maine |
24001 |
Allegany County |
Maryland |
24003 |
Anne Arundel County |
Maryland |
24005 |
Baltimore County |
Maryland |
24013 |
Carroll County |
Maryland |
24021 |
Frederick County |
Maryland |
24023 |
Garrett County |
Maryland |
24025 |
Harford County |
Maryland |
24027 |
Howard County |
Maryland |
24031 |
Montgomery County |
Maryland |
24033 |
Prince George's County |
Maryland |
24043 |
Washington County |
Maryland |
24510 |
Baltimore city |
Maryland |
25003 |
Berkshire County |
Massachusetts |
26009 |
Antrim County |
Michigan |
26013 |
Baraga County |
Michigan |
26029 |
Charlevoix County |
Michigan |
26033 |
Chippewa County |
Michigan |
26041 |
Delta County |
Michigan |
26047 |
Emmet County |
Michigan |
26053 |
Gogebic County |
Michigan |
26055 |
Grand Traverse County |
Michigan |
26061 |
Houghton County |
Michigan |
26079 |
Kalkaska County |
Michigan |
26083 |
Keweenaw County |
Michigan |
26089 |
Leelanau County |
Michigan |
26103 |
Marquette County |
Michigan |
26131 |
Ontonagon County |
Michigan |
26137 |
Otsego County |
Michigan |
26153 |
Schoolcraft County |
Michigan |
27001 |
Aitkin County |
Minnesota |
27005 |
Becker County |
Minnesota |
27007 |
Beltrami County |
Minnesota |
27021 |
Cass County |
Minnesota |
27027 |
Clay County |
Minnesota |
27029 |
Clearwater County |
Minnesota |
27033 |
Cottonwood County |
Minnesota |
27061 |
Itasca County |
Minnesota |
27063 |
Jackson County |
Minnesota |
27081 |
Lincoln County |
Minnesota |
27083 |
Lyon County |
Minnesota |
27089 |
Marshall County |
Minnesota |
27101 |
Murray County |
Minnesota |
27105 |
Nobles County |
Minnesota |
27107 |
Norman County |
Minnesota |
27111 |
Otter Tail County |
Minnesota |
27117 |
Pipestone County |
Minnesota |
27119 |
Polk County |
Minnesota |
27133 |
Rock County |
Minnesota |
27137 |
St. Louis County |
Minnesota |
27167 |
Wilkin County |
Minnesota |
29045 |
Clark County |
Missouri |
29199 |
Scotland County |
Missouri |
30003 |
Big Horn County |
Montana |
30047 |
Lake County |
Montana |
30071 |
Phillips County |
Montana |
30073 |
Pondera County |
Montana |
30077 |
Powell County |
Montana |
30081 |
Ravalli County |
Montana |
30085 |
Roosevelt County |
Montana |
30089 |
Sanders County |
Montana |
30093 |
Silver Bow County |
Montana |
30099 |
Teton County |
Montana |
30105 |
Valley County |
Montana |
31031 |
Cherry County |
Nebraska |
32031 |
Washoe County |
Nevada |
33001 |
Belknap County |
New Hampshire |
33003 |
Carroll County |
New Hampshire |
33007 |
Coos County |
New Hampshire |
33009 |
Grafton County |
New Hampshire |
33013 |
Merrimack County |
New Hampshire |
33015 |
Rockingham County |
New Hampshire |
33017 |
Strafford County |
New Hampshire |
33019 |
Sullivan County |
New Hampshire |
34001 |
Atlantic County |
New Jersey |
34005 |
Burlington County |
New Jersey |
34007 |
Camden County |
New Jersey |
34009 |
Cape May County |
New Jersey |
34011 |
Cumberland County |
New Jersey |
34015 |
Gloucester County |
New Jersey |
34019 |
Hunterdon County |
New Jersey |
34021 |
Mercer County |
New Jersey |
34023 |
Middlesex County |
New Jersey |
34025 |
Monmouth County |
New Jersey |
34027 |
Morris County |
New Jersey |
34029 |
Ocean County |
New Jersey |
34031 |
Passaic County |
New Jersey |
34033 |
Salem County |
New Jersey |
34035 |
Somerset County |
New Jersey |
34037 |
Sussex County |
New Jersey |
34039 |
Union County |
New Jersey |
34041 |
Warren County |
New Jersey |
35055 |
Taos County |
New Mexico |
36001 |
Albany County |
New York |
36011 |
Cayuga County |
New York |
36019 |
Clinton County |
New York |
36025 |
Delaware County |
New York |
36031 |
Essex County |
New York |
36033 |
Franklin County |
New York |
36035 |
Fulton County |
New York |
36039 |
Greene County |
New York |
36041 |
Hamilton County |
New York |
36043 |
Herkimer County |
New York |
36045 |
Jefferson County |
New York |
36047 |
Kings County |
New York |
36049 |
Lewis County |
New York |
36053 |
Madison County |
New York |
36057 |
Montgomery County |
New York |
36065 |
Oneida County |
New York |
36067 |
Onondaga County |
New York |
36075 |
Oswego County |
New York |
36083 |
Rensselaer County |
New York |
36089 |
St. Lawrence County |
New York |
36091 |
Saratoga County |
New York |
36093 |
Schenectady County |
New York |
36095 |
Schoharie County |
New York |
36103 |
Suffolk County |
New York |
36111 |
Ulster County |
New York |
36113 |
Warren County |
New York |
36115 |
Washington County |
New York |
36119 |
Westchester County |
New York |
37011 |
Avery County |
North Carolina |
37021 |
Buncombe County |
North Carolina |
37075 |
Graham County |
North Carolina |
37087 |
Haywood County |
North Carolina |
37089 |
Henderson County |
North Carolina |
37099 |
Jackson County |
North Carolina |
37113 |
Macon County |
North Carolina |
37115 |
Madison County |
North Carolina |
37121 |
Mitchell County |
North Carolina |
37173 |
Swain County |
North Carolina |
37175 |
Transylvania County |
North Carolina |
37199 |
Yancey County |
North Carolina |
38003 |
Barnes County |
North Dakota |
38005 |
Benson County |
North Dakota |
38017 |
Cass County |
North Dakota |
38019 |
Cavalier County |
North Dakota |
38027 |
Eddy County |
North Dakota |
38035 |
Grand Forks County |
North Dakota |
38039 |
Griggs County |
North Dakota |
38063 |
Nelson County |
North Dakota |
38067 |
Pembina County |
North Dakota |
38071 |
Ramsey County |
North Dakota |
38073 |
Ransom County |
North Dakota |
38077 |
Richland County |
North Dakota |
38081 |
Sargent County |
North Dakota |
38091 |
Steele County |
North Dakota |
38097 |
Traill County |
North Dakota |
38099 |
Walsh County |
North Dakota |
39007 |
Ashtabula County |
Ohio |
39035 |
Cuyahoga County |
Ohio |
39055 |
Geauga County |
Ohio |
39085 |
Lake County |
Ohio |
41029 |
Jackson County |
Oregon |
41035 |
Klamath County |
Oregon |
41037 |
Lake County |
Oregon |
41059 |
Umatilla County |
Oregon |
41065 |
Wasco County |
Oregon |
42011 |
Berks County |
Pennsylvania |
42025 |
Carbon County |
Pennsylvania |
42027 |
Centre County |
Pennsylvania |
42035 |
Clinton County |
Pennsylvania |
42039 |
Crawford County |
Pennsylvania |
42045 |
Delaware County |
Pennsylvania |
42049 |
Erie County |
Pennsylvania |
42071 |
Lancaster County |
Pennsylvania |
42077 |
Lehigh County |
Pennsylvania |
42081 |
Lycoming County |
Pennsylvania |
42089 |
Monroe County |
Pennsylvania |
42095 |
Northampton County |
Pennsylvania |
42101 |
Philadelphia County |
Pennsylvania |
42111 |
Somerset County |
Pennsylvania |
42125 |
Washington County |
Pennsylvania |
42127 |
Wayne County |
Pennsylvania |
45045 |
Greenville County |
South Carolina |
45073 |
Oconee County |
South Carolina |
45077 |
Pickens County |
South Carolina |
46011 |
Brookings County |
South Dakota |
46051 |
Grant County |
South Dakota |
46067 |
Hutchinson County |
South Dakota |
46077 |
Kingsbury County |
South Dakota |
46083 |
Lincoln County |
South Dakota |
46087 |
McCook County |
South Dakota |
46099 |
Minnehaha County |
South Dakota |
46101 |
Moody County |
South Dakota |
46109 |
Roberts County |
South Dakota |
46125 |
Turner County |
South Dakota |
49047 |
Uintah County |
Utah |
50001 |
Addison County |
Vermont |
50003 |
Bennington County |
Vermont |
50005 |
Caledonia County |
Vermont |
50007 |
Chittenden County |
Vermont |
50011 |
Franklin County |
Vermont |
50013 |
Grand Isle County |
Vermont |
50015 |
Lamoille County |
Vermont |
50017 |
Orange County |
Vermont |
50019 |
Orleans County |
Vermont |
50021 |
Rutland County |
Vermont |
50023 |
Washington County |
Vermont |
50025 |
Windham County |
Vermont |
50027 |
Windsor County |
Vermont |
51017 |
Bath County |
Virginia |
51043 |
Clarke County |
Virginia |
51059 |
Fairfax County |
Virginia |
51069 |
Frederick County |
Virginia |
51079 |
Greene County |
Virginia |
51107 |
Loudoun County |
Virginia |
51113 |
Madison County |
Virginia |
51139 |
Page County |
Virginia |
51153 |
Prince William County |
Virginia |
51157 |
Rappahannock County |
Virginia |
51165 |
Rockingham County |
Virginia |
51171 |
Shenandoah County |
Virginia |
51187 |
Warren County |
Virginia |
51540 |
Charlottesville city |
Virginia |
51820 |
Waynesboro city |
Virginia |
53025 |
Grant County |
Washington |
53047 |
Okanogan County |
Washington |
53071 |
Walla Walla County |
Washington |
53077 |
Yakima County |
Washington |
54003 |
Berkeley County |
West Virginia |
54023 |
Grant County |
West Virginia |
54027 |
Hampshire County |
West Virginia |
54031 |
Hardy County |
West Virginia |
54037 |
Jefferson County |
West Virginia |
54057 |
Mineral County |
West Virginia |
54065 |
Morgan County |
West Virginia |
54067 |
Nicholas County |
West Virginia |
54075 |
Pocahontas County |
West Virginia |
54083 |
Randolph County |
West Virginia |
54093 |
Tucker County |
West Virginia |
54101 |
Webster County |
West Virginia |
55003 |
Ashland County |
Wisconsin |
55007 |
Bayfield County |
Wisconsin |
55021 |
Columbia County |
Wisconsin |
55025 |
Dane County |
Wisconsin |
55027 |
Dodge County |
Wisconsin |
55031 |
Douglas County |
Wisconsin |
55039 |
Fond du Lac County |
Wisconsin |
55045 |
Green County |
Wisconsin |
55047 |
Green Lake County |
Wisconsin |
55049 |
Iowa County |
Wisconsin |
55051 |
Iron County |
Wisconsin |
55055 |
Jefferson County |
Wisconsin |
55059 |
Kenosha County |
Wisconsin |
55065 |
Lafayette County |
Wisconsin |
55075 |
Marinette County |
Wisconsin |
55077 |
Marquette County |
Wisconsin |
55079 |
Milwaukee County |
Wisconsin |
55083 |
Oconto County |
Wisconsin |
55089 |
Ozaukee County |
Wisconsin |
55101 |
Racine County |
Wisconsin |
55105 |
Rock County |
Wisconsin |
55111 |
Sauk County |
Wisconsin |
55117 |
Sheboygan County |
Wisconsin |
55125 |
Vilas County |
Wisconsin |
55127 |
Walworth County |
Wisconsin |
55131 |
Washington County |
Wisconsin |
55133 |
Waukesha County |
Wisconsin |
56007 |
Carbon County |
Wyoming |
56021 |
Laramie County |
Wyoming |
56031 |
Platte County |
Wyoming |
56045 |
Weston County |
Wyoming |
Hazard samples will also be stratified by census region and so each of the four strata for any hazard will consist of counties identified for that hazard in that particular census region. The sample allocation across strata will be proportional to the size of the stratum derived as the estimated total adult population of the counties selected for that hazard in that particular stratum. As proposed for national sample, both landline and cell phone numbers will be included in hazard area samples and the total number of completed surveys will be roughly split equally between the landline and cell phone samples. For within household selection of respondent, the most recent birthday method will be used. For cell phone sample, the person answering the phone will be selected for interview as long as he/she is otherwise found eligible for the survey.
-Estimation procedure:
Each of the five samples (the national and the four hazard samples) will be weighted independently. Once those weights are finalized, the sample data consisting of the national sample (1,000 completed surveys) and four hazard area level surveys (500 completes each) will also be combined (composite weighting) and then weighted (post-stratified) to generate estimates for unknown populations parameters at various levels (national, regional or for other subgroups of interest).
For the National sample, weighting will be carried out within each stratum (region) to adjust for (i) unequal probability of selection in the sample and (ii) nonresponse. Once the sampling weights are generated, weighted estimates can be produced for different unknown population parameters (means, proportions etc.) for the target population and also for population subgroups.
The weighting for this study will be done following the basic approach described in Kennedy, Courtney (2007): Evaluating the Effects of Screening for Telephone Service in Dual Frame RDD Surveys, Public Opinion Quarterly, Special Issue 2007, Volume 71 / Number 5: 750-771. In studies dealing with both landline and cell phone samples, one approach is to screen for “cell only” respondents by asking respondents reached on the cell phones whether or not they also have access to a landline and then interviewing all eligible persons from the landline sample whereas interviewing only “cell only” persons from the cell phone sample. The samples from such designs are stratified, with each frame constituting its own stratum. In this study, however, a dual-frame design is proposed where dual users (those with access to both landline and cell phones) can be interviewed in either sample. This will result in two estimates for the dual users based on the two samples (landline and cell). The two estimates for the dual users will then be combined and added to the estimates based on landline-only and cell-only population to generate the estimate for the whole population.
Composite pre-weight— For the purpose of sample weighting of the national sample, the four census regions will be used as weighting adjustment classes. Following Kennedy, Courtney (2007), the composite pre-weight will be generated within each weighting class. The weight assigned to the ith respondent in the hth weighting class (h=1, 2, 3, 4) will be calculated as follows:
W(landline,hi) = (Nhl/nhl)(1/RRhl)(ncwa/nll)(λIDual) for landline sample cases (1)
W(Cell,hi) = (Nhc/nhc)(1/RRhc)(1 – λ)IDual for cellular sample cases (2)
where
Nhl: size of the landline RDD frame in weighting class h
nhl: sample size from landline frame in weighting class h
RRhl: response rate in weighting class h associated with landline frame
ncwa: number of adults in the sampled household
nll: number of residential telephone landlines in sampled household
IDual: indicator variable with value 1 if the respondent is a dual user and value 0 otherwise
Nhc: size of the Cell RDD frame in weighting class h
nhc: sample size from Cell frame in weighting class h
RRhc: response rate in weighting class h associated with Cell frame
‘λ’ is the “mixing parameter” with a value between 0 and 1. If roughly the same number of dual users is interviewed from both samples (landline and cell) within each census region, then 0.5 will serve as a reasonable approximation to the optimal value for λ. This adjustment of the weights for the dual users based on the value of the mixing parameter ‘λ’ will be carried out within each census region. For this study, the plan is to use a value of ‘λ’ equal to the ratio of the number of dual users interviewed from the landline frame and the total number dual users interviewed from both frames within each region.
It may be noted that equation (2) above for cellular sample cases doesn’t include weighting adjustments for (i) number of adults and (ii) telephone lines. For cellular sample cases, as mentioned before, there is no within-household random selection. The random selection can be made from all persons sharing a cell phone but the percentage of those sharing a cell phone is rather small and it will also require additional questionnaire time to try to capture such information. The person answering the call will be selected as the respondent if he or she is otherwise found eligible and hence no adjustment based on “number of eligible adults in the household” will be necessary. The information on the number of cell phones owned by a respondent could also be asked to make adjustments based on number of cell phones. However, the percentage of respondents owning more than one cell phone is expected to be too low to have any significant impact on sampling weights. For landline sample cases, the values for (i) number of adults (ncwa) and (ii) number of residential telephone lines (nll) may have to be truncated to avoid extreme weights. The cutoff value for truncation will be determined after examining the distribution of these variables in the sample. It is anticipated that these values may be capped at 2 or 3.
Response rate: The response rates (RRhl and RRhc mentioned above in equations (1) and (2)), will be measured using the AAPOR (3) definition of response rate within each weighting class and will be calculated as follows:
RR = (number of completed interviews) / (estimated number of eligibles)
= (number of completed interviews) / (known eligibles + presumed eligibles)
It will be straightforward to find the number of completed interviews and the number of known eligibles. The estimation of the number of “presumed eligibles” will be done in the following way: In terms of eligibility, all sample records (irrespective of whether any contact/interview was obtained) may be divided into three groups: i) known eligibles (i.e., cases where the respondents, based on their responses to screening questions, were found eligible for the survey), ii) known ineligibles (i.e., cases where the respondents, based on their responses to screening questions, were found ineligible for the survey), and iii) eligibility unknown (i.e., cases where all screening questions could not be asked, as there was never any human contact or cases where respondents answered the screening questions with a “Don’t Know” or “Refused” response and hence the eligibility is unknown).
Based on cases where the eligibility status is known (known eligible or known ineligible), the eligibility rate (ER) is computed as:
ER = (known eligibles) / (known eligibles + known ineligibles)
Thus, the ER is the proportion of eligibles found in the group of respondents for whom the eligibility could be established.
At the next step, the number of presumed eligibles is calculated as:
Presumed eligibles = ER × number of respondents in the eligibility unknown group
The basic assumption is that the eligibility rate among cases where eligibility could not be established is the same as the eligibility rate among cases where eligibility status was known. The response rate formula presented above is based on standard guidelines on definitions and calculations of Response Rates provided by AAPOR (American Association for Public Opinion Research).
Post-stratification weight— Once the landline and cell samples are combined using the composite weight (equations (1) and (2) above), a post-stratification weighting step will be carried out, following Kennedy (2007), to simultaneously rake the combined sample to (i) known characteristics of the target population (adults 18 years of age or older) and (ii) an estimated parameter for relative telephone usage (landline-only, cell only, cell mostly, other dual users). The demographic variables to be used for weighting will include Age, gender, Race, Ethnicity (Hispanic/Non-Hispanic), and Education. The target numbers for post-stratification weighting will be obtained from the latest available Current Population Survey (CPS) data. The collapsing of categories for post-stratification weighting may become necessary where the sample sizes are going to be relatively small.
The target numbers for the relative telephone usage parameter will be based on the latest estimates from NHIS (National Health Interview Survey). For the purpose of identifying the “cell mostly” respondents among the group of dual users, a question similar to the following question will be included in the survey.
Question: Of all the telephone calls your household receives (read 1-3)?
1 All or almost all calls are received on cell phones
2 Some are received on cell phones and some on regular phones, OR
3 Very few or none are received on cell phones
4 (DK)
5 (Refused)
Respondents choosing response category 1 (all or almost all calls are received on cell phones) will be identified as “cell mostly” respondents.
After post-stratification weighting, the distribution of the final weights will be examined and trimming of extreme weights, if any, will be carried out if necessary to minimize the effect of large weights on variance of estimates.
Each of the four hazard samples will be weighted separately following procedures similar to those described above for the national sample. For the hazard samples, the weighting classes will be based on county (or groups of counties) depending on the definition of specific counties. Once each of the five samples (the national and the four hazard samples) are weighted separately, they will also be pulled together into one combined sample using composite weighting. The combined sample will then be post-stratified to known characteristics of the target population (i.e. the national population) for this study.
-Degree of accuracy needed for the purpose described in the justification:
We plan to complete about 3,000 completed telephone interviews per administration including about 1,000 interviews using a national level sample and around 500 interviews each for each of the hazard areas. The survey estimates of unknown population parameters (for example, population proportions) based on a sample size of 3,000 will have a precision (margin of error) of about +1.8 percentage points at 95% level of significance. This is under the assumption of no design effect and also under the most conservative assumption that the unknown population proportion is around 50%. The margin of error (MOE) for estimating the unknown population proportion ‘P’ at the 95% confidence level can be derived based on the following formula:
MOE = 1.96 * where “n” is the sample size (i.e. the number of completed surveys).
In this survey, where the total sample size (3,000) will include oversamples from four hazard areas and therefore may be subject to a relatively higher design effect. A design effect of 2, for example, will result in effective sample size of 1,500 and a margin of error around +2.5% at 95% confidence level. The sampling error associated with an estimate based on just the national sample size of 1,000 with a design effect of 1.25 will still be below ±3.5 points. For each of the hazard areas with about 500 completed interviews, an estimate for an unknown population proportion will have margin of error around ±4.4 points ignoring any design effect. With an anticipated design effect of about 1.25, the precision will be around ±4.9 percentage points. Hence, the accuracy and reliability of the information collected in this study will be adequate for its intended uses. The sampling error of estimates for this survey will be computed using special software (like SUDAAN) that calculates standard errors of estimates by taking into account the complexity, if any, in the sample design and the resulting set of unequal sample weights.
The necessary sample size for a two-sample proportion test (one-tailed test) can be derived as follows:
n = [{z(1-α) SQRT (2p*q*) + z(1-β) SQRT(p1q1 + p2q2)} /{p2 – p1)}] 2 (3)
where
n: sample size (number of completed surveys) required per group to achieve the desired statistical power
z(1-α), z(1-β) are the normal abscissas that correspond to the respective probabilities
p1, p2 are the two proportions in the two-sample test
and p* is the simple average of p1 and p2 and q* = 1 – p*.
For example, the required sample size, ignoring any design effect, will be around 310 per group (top and bottom halves) with β=.2 (i.e., with 80% power), α=.05 (i.e., with 5% level of significance), and p1=.55 and p2=0.45. The sample size requirement is highest when p1 and p2 are around 50% and so, to be most conservative, those values (.55 and .45) of p1 and p2 were chosen. The proposed sample size will therefore meet the sample size requirements for estimation and testing statistical hypotheses not only at the national level but also for a wide variety of subgroups that may be of special interest in this study.
-Unusual problems requiring specialized sampling procedures: (e.g., special hard to reach populations, bias toward landline verses cell phone respondents, populations that need to be reached via other methods such as those who do not use telephones for religious reasons, large non-English speaking populations expected to be surveyed but only English questionnaires available, exclusion of elderly using computer response only, etc.)
Note: For surveys with particularly low response rates and a substantial suspicion of non-response bias, it may be necessary to collect an additional sub-sample of completed surveys from non-respondents in order to confirm if non-response bias is present in the sample and make adjustments if appropriate.
Unusual problems requiring specialized sampling procedures are not anticipated at this time. If response rates fall below the expected levels, additional sample will be released to generate the targeted number of surveys. However, all necessary steps to maximize response rates will be taken throughout the data collection period and hence such situations are not anticipated.
-Any use of periodic (less frequent than annual) data collection cycles to reduce burden:
During each administration of the survey, independent samples will be drawn and so the probability of selecting the same respondent in multiple administrations will be quite low.
Describe methods to maximize response rates and to deal with issues of non-response. The accuracy and reliability of information collected must be shown to be adequate for intended uses. For collections based on sampling, a special justification must be provided for any collection that will not yield “reliable” data that can be generalized to the universe studied.
Methods to maximize response rates— In order to maximize response rates, Gallup will use a comprehensive plan that focuses on (1) a call design that will ensure call attempts are made at different times of the day and different days of the week to maximize contact rates, (2) conducting an extensive interviewer briefing prior to the field period that educates interviewers about the content of the survey as well as how to handle reluctance and refusals, (3) having strong supervision that will ensure that high-quality data are collected throughout the field period, (4) using troubleshooting teams to attack specific data collection problems that may occur during the field period, and (5) customizing refusal aversion techniques. A 5 + 5 call design, i.e., a maximum of five calls will be made on the phone number to reach the specific person we are attempting to contact and up to another five calls will be made to complete the interview with that selected person.
Issues of Non-Response— Survey based estimates for this study will be weighted to minimize any potential bias, including any bias that may be associated with unit level nonresponse. All estimates will be weighted to reduce bias and it will be possible to calculate the sampling error associated with any subgroup estimate in order to ensure that the accuracy and reliability is adequate for intended uses of any such estimate. Based on experience from conducting similar surveys previously and given that the mode of data collection for the proposed survey is telephone, the extent of missing data at the item level is expected to be minimal. We, therefore, do not anticipate using any imputation procedure to handle item-level missing data.
Non-response bias Study and analysis— A nonresponse bias analysis will be conducted to examine the non-response pattern and identify potential sources of nonresponse bias. No additional follow-up data collection for the non-respondents is planned for this study. Hence the proposed non-response analysis will be based on survey data collected in the main survey.
Nonresponse bias associated with estimates consists of two factors—the amount of nonresponse and the difference in the estimate between the groups of respondents and non-respondents. Bias may therefore be caused by significant differences in estimates between respondents and non-respondents further magnified by lower response rates. As described earlier in this section, necessary steps will be taken to maximize response rates and thereby minimize the effect, if any, of lower non-response rates on non-response bias. Also, nonresponse weighting adjustments will be carried out to minimize potential nonresponse bias. However, despite all these attempts, nonresponse bias can still persist in estimates.
As part of the non-response analysis, the respondents will be split into two groups: (i) early or ‘easy to reach’ and (ii) late or ‘difficult to reach’ respondents. The call design for this survey, as mentioned before, will be 5 + 5 and so a maximum of up to 10 calls may be made to each sampled phone number. The total number of calls required to complete an interview with a respondent will be used to identify these two groups – “early” and “late” respondents. This comparison will be based on the assumption that the latter group may in some ways resemble the population of non-respondents. The goal of the analysis plan will be to assess the nature of non-response pattern in this survey. Nonresponse bias analysis may also involve comparison of survey-based estimates of important characteristics of the adult population to external estimates. This process will help identify estimates that may be subject to nonresponse bias. If non-response is found to be associated with certain variables, then weighting based on those variables will be attempted to minimize non-response bias.
Note: Describe all possible actions you plan to take to maximize response including incentives, call-backs, follow up, survey length kept to a minimum to increase participation, letters urging the importance of their contribution to this data collection, etc.
4. Describe any tests of procedures or methods to be undertaken. Testing is encouraged as an effective means of refining collections of information to minimize burden and improve utility. Tests must be approved if they call for answers to identical questions from 10 or more respondents. A proposed test or set of tests may be submitted for approval separately or in combination with the main collection of information.
The CATI survey will be tested with fewer than 10 respondents, prior to fielding, to ensure correct skip patterns and procedures.
5. Provide the name and telephone number of individuals consulted on statistical aspects of the design and the name of the agency unit, contractor(s), grantee(s), or other person(s) who will actually collect and/or analyze the information for the agency.
The information collection is conducted for the Individual and Community Preparedness Division by a contractor:
The representatives of the contractor who consulted on statistical aspects of design are:
Camille Lloyd
Research Director
Gallup Inc.
901 F Street NW
Washington, DC 20004
202-715-3188
Manas Chattopadhyay
Chief Methodologist
Gallup Inc.
901 F Street NW
Washington, DC 20004
202-715-3030
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