General information

The California Sample Batch 2 sample cohort is characterized by the following:

Batch code16
Sample descriptionCalifornia Representative
Date drawnFebruary 13, 2018
Date of first mailingMarch 23, 2018
Batch size4962

Recruitment rates

All the recruitment rates below conform to AAPOR specifications. Please note that the Initial Response Rate reported in table 1 are based on AAPOR RR1. More information about the AAPOR response rates can be found at the Aapor web site.

Mailout and phone follow up of initial survey

The initial mail survey is a standard paper and pencil mail survey, but the respondents are given the option to respond online. The response rate of this is computed like any mail survey.

Total sample4,962
Eligible refusals and noncontacts (R)
Refused to participate0
Incomplete interviews1
Refusals and noncontacts with unknown eligibility (U)
Nothing returned3,295
Unreachable by phone0
Undeliverable by mail317
Responses (I)1,349
Initial Response Rate (I/(I + R + U))29%

Consent to participate

The initial mail survey asks respondents whether they would be interested in participating in the Understanding America Study. Everyone who answers affirmatively and who receives a login code is considered to have provided consent. The recruitment rate is then calculated as the number of people who receive a login code divided by the total number of eligible responses to the mail survey.

Total sample1,349
Eligible refusals and noncontacts (R)
Refused to participate312
Refusals and noncontacts with unknown eligibility (U)0
Responses (I)1,037
Recruitment Rate (I/(I + R + U))76.9%

Initial participation

The profile rate (PROR) is the fraction of the individuals who consented who completed My Household and thus became a panel member.

Total sample1,037
Eligible refusals and noncontacts (R)
Logged on to survey, did not complete any item0
Partially completed the My Household survey26
Did not log on422
Responses (I)589
Profile Rate (I/(I + R))56.8%

Overall recruitment rate

The overall recruitment rate (ORR) is the product of the response rates computed above (initial response rate, recruitment rate, and profile rate):

ORR = IRR * RECR * PROR = 0.29 * 0.769 * 0.568 = 12.7%

Active panel

As in any panel, we monitor attrition. Because individuals often simply stop responding without actively withdrawing from the panel and without us being able to contact them, we adopt the criterion that an individual is considered to be an active panel member if they participated in any survey in the last year (counting back from today, that is, June 10, 2023). A panel member who is not an active panel member but has not been removed yet from the panel is an inactive panel member.

Total sample589
Eligible refusals and noncontacts (R)
Voluntary drop-out25
Temporarily unavailable1
Individuals removed for miscellaneous reasons17
Refusals and noncontacts with unknown eligibility (U)
Inactive panel member212
Ineligible for another reason0
Responses (I)332
Retention Rate (I/(I + R + U)56.6%

Cumulative response rate

The cumulative response rate (CUMRR) up to and including retention is the product of the response rates computed above (initial response rate, recruitment rate, profile rate, and retention rate):

CUMRR = IRR * RECR * PROR * RETR = 0.29 * 0.769 * 0.568 * 0.566 = 7.2%