Sample and Recruitment
Recruiting takes place via Address Based Sampling (ABS), for which postal records are used. Zip codes are drawn randomly from across the nation. Within zip-codes a sample of addresses are drawn randomly, to which a pre-notification letter is sent followed by a mail survey. On the last page of the paper survey, prospective respondents are asked if they want to join the UAS panel. If they express interest, they are invited to regularly participate in online surveys. A detailed description of the recruitment protocol is below.
The recruiting procedure has the following stages:
- Draw zip-codes; buy post office delivery sequence files from a commercial vendor.
- Send an advance notification letter (English/Spanish) to the selected households; whenever possible these letters have a named addressee; Letters to "current resident" are only used in cases where we only have an address but no other information.1
- One week later the named respondent in the selected household (or the "current resident") receives by Priority Mail a 10 minute mail survey (English/Spanish) with a $5 prepaid incentive and a promise of $15 upon the return of a completed questionnaire via the enclosed postage paid envelope. The survey asks about labor market status; computer use; educational attainment; various questions about the household's financial situation and the respondent's assessment of the economy as a whole; health and health insurance; life satisfaction. At the end of the questionnaire, the survey asks for interest in study participation in other research projects. Those who express an interest in study participation are asked for contact information (name, telephone, email address).
- 2 weeks after the survey mailing, non-respondents are mailed a reminder postcard.
- 2 weeks after the reminder postcard has been mailed, a second copy of the survey is mailed by regular mail to all sample members who have not returned a completed survey, with the option to now complete the same survey online (a web address is given.) The letter also mentions the possibility that a different household member completes the survey.
- 3 weeks after the second copy of the survey is mailed, follow-up phone calls are initiated for all households for whom a phone number is available with up to 15 attempts. Again, if a respondent refuses to answer the survey, the option is mentioned that a different household member answers the survey.
- Households who have returned their mail survey and agree to be contacted again receive:
- Welcome brochure
- Prepaid card with $15 loaded
- Welcome letter with login information and a notice we will accept all household members 18+ into study if we are provided with their contact information (preferably name, telephone number, and email address); the letter notices that the first time they log in and answer the first brief survey ("My Household", asking for basic demographic and socio-economic information), they will get a bonus of $20. The letter also notices that any other household member who would join the panel and answers "My Household" will also receive $20.
- If no email was given in the written survey, their letter includes a request for email address or offer to assist in setting up and email account.
- If internet is needed (we will know that from the brief written survey), a consent form and return envelope is included so we can set up a tablet plus broadband internet for respondent, one per household.
- A form for additional household members to provide their name and email address and a return envelope.
- If respondent was not interested in participating in future research, a $15 payment and thank you letter is mailed 2. The letter includes the offer for other household members to join UAS, even if the primary respondent refuses. A form for the other household members to provide their contact information and a return envelope are included.
- Households who log into the UAS web-site are asked to agree to an online consent before they take the first survey ("My Household"). Households with at least one member who has answered "My Household" are considered UAS panel members. Respondents are reminded once again that other household members 18 and older are also eligible to become panel members. The respondent's log-in page has a "other household member may be interested" button they may click on to enter the other household member's email address. This triggers an automatic email invitation to the other household member to become a UAS panel member. Participating household members get paid for the surveys they take at a rate of $20 per 30 minutes (and proportionately less if a survey is shorter). All UAS panel members receive a prepaid debit card, to which new money is added every month depending on how many surveys they have taken.
- Household respondents who have agreed to become panel members, but next fail to log on to the UAS web-site, are contacted by email if we have their email address or mail if they refuse to give us their email. If they don't respond (or if their email address is not available/valid) they are contacted by phone (whenever possible) to encourage them to log on, and to offer help if there are any barriers to logging on (such as a user name and password that may have been lost). They are told once again they will receive $20 upon finishing the first brief survey ("My Household").
- The final stage is an "end-game", whereby the households who have internet access, who have not logged in four weeks after last contact (either the My Household email/letter reminder or the phone follow-up where that was feasible), receive a FedEx envelope (or Priority Mail envelope if we are delivering to a post office box) with an offer of $40 for logging in and answering "My Household. We have a one-week deadline printed in the endgame letter with a due date.
Fielding questions in the UAS
The UAS elicits demographic information, such as age, ethnicity, education, marital status, work status, state of residence, family structure, etc., on a regular basis through the My Household questionnaire. Specifically, respondents are required to provide or update their demographic information every quarter. Failure to answer the My Household questionnaire once it is due prevents respondents from participating in any other surveys until they do so.
When a research survey is ready for the field, UAS panelists receive an email or postcard inviting them to participate. Included is a one-sentence description of the survey, as well as an estimate of the time it should take to complete, a deadline (if there is one) and the pay they will receive for completion. Study members receive $20 for every 30 minutes of survey time. They are paid monthly via funds added to a prepaid card provided by the UAS. Study participants expect at least one survey each month and most welcome more.
At the end of each questionnaire, respondents are asked to rate their interest in the survey. Study members also participate in an annual survey measuring the performance of the UAS help desk and their overall experience in the study, including their preferred survey topics. Data from these surveys is available at no charge and only requires a data login. (Register here.)
Eligible individuals are all adults aged 18 and older in the contacted household. In this context, a household is broadly defined as anyone living together with the initial person who signed up to become a participant in the UAS. If a household is willing to participate but not in possession of Internet access and/or a computer or tablet, a tablet and broadband Internet are provided for their use during the study's duration.
The UAS includes special-purpose samples of Native Americans and Los Angeles County families with young children. In the case of the former, ABS recruitment targets zip codes with a higher proportion of Native Americans; non-Native American primary respondents in these zip codes are not invited to join. For the latter, this sample is recruited using birth records information from the State of California, which provides addresses of households in Los Angeles County where children were born during the previous five years.
Thus far, the recruitment has comprised the sample batches listed below. Please note that the recruiting process on average takes approximately six months for most sampled respondents to log in to the UAS survey page for the first time. So for more recent batches the response overview may reflect results that are not yet complete. As a matter of fact, in our experience some sample members may join many months after the last reminder has been sent out. At this point, probably the recruiting of all batches through January 2016 can be considered to be complete. Also note that the list below is updated regularly to include new sample batches. To learn more about a batch and its response details please just click on its name. All percentages reported below are all taken relative to the total number of mailed out surveys minus survey mailed to addresses that were found to be non-existent of invalid (e.g. business addresses).
|Name||Initial mail out||Experiment||Gross sample||Completed mail survey||Consented to participate||Became panel member||Active|
|ASDE 2014-01 Nationally Representative||February 21, 2014||None||9287||42.9%||34.8%||19.5%||14.4%|
|ASDE 2014-01 Native American3||June 9, 2014||None||4064||45.4%||4.6%||3.5%||3.2%|
|ASDE 2014-11 Native American3||January 3, 2015||None||4225||40.9%||3.0%||2.6%||2.3%|
|LA County 2015/05 List Sample||April 14, 2015||None||1771||31.0%||28.1%||14.0%||10.5%|
|MSG 2015-07 Nationally Representative Batch 1||September 4, 2015||None||1799||40.4%||30.4%||13.7%||11.9%|
|MSG 2016-01 Nationally Representative Batch 2||January 26, 2016||None||3216||45.2%||31.1%||15.0%||14.2%|
|MSG 2016-01 Nationally Representative Batch 3||February 17, 2016||A random subset of the sample received an envelope addressed as 'Name or Current Resident' ('Current Resident' only if no name available).|
A random subset of the envelopes had a colorful label.
|MSG 2016-01 Nationally Representative Batch 4||March 1, 2016||Half of the sample received an envelope by Priority Mail, the other half by regular mail.||3370||38.7%||26.9%||14.3%||13.7%|
|MSG 2016-02 Nationally Representative Batch 5||March 15, 2016||Postcard treatment $5 recruitment strategy||3309||38.8%||26.3%||14.6%||14.1%|
|MSG 2016-03 Nationally Representative Batch 6||April 22, 2016||Personalized Postcard And Letter||3388||40.0%||27.6%||14.9%||14.3%|
|MSG 2016-04 Nationally Representative Batch 7||May 16, 2016||None||3462||39.1%||27.8%||13.1%||12.5%|
|MSG 2016-05 Nationally Representative Batch 8||June 27, 2016||None||3483||40.6%||30.3%||14.4%||14.0%|
|LA County 2016/08 List Sample 2||August 12, 2016||None||1950||31.4%||24.3%||13.1%||12.4%|
2: Native American samples were screened for ethnicity. Welcome Letters were only sent to appropriate ethnic groups, while other respondents are sent a letter thanking them for their interest, and mentioning we may contact them in the future should opportunities arise.
3: the relatively small numbers for the Native Americans are due to ineligibility, not unwillingness to participate