AJC 2015 Survey of American Jewish Opinion
2015 Survey of American Jewish Opinion - Press Release
This questionnaire for this survey was designed by the staff of AJC (American Jewish Committee). This survey was administered on behalf of AJC by GfK, and data collection utilized their proprietary KnowledgePanel®, a web-based respondent panel designed to be representative of the United States population of non-institutionalized adults 18+ years of age.
Questionnaires were completed online by panelists who were invited to participate due to meeting either of two qualification criteria (in a previously administered profile interview): they identified their religion as “Jewish” or they said they considered themselves Jewish for any other reason. 1,386 qualified panelists were invited to participate in this survey, and 1,030 completed the questionnaire during the period August 7 - 22, 2015.
General GfK Methodology
The following description of the panel recruitment and survey administration was provided by GfK.
GfK has recruited the first online research panel that is representative of the entire U.S. population. Panel members are randomly recruited through probability-based sampling, and households are provided with access to the Internet and hardware if needed.
GfK selects households by using address-based sampling methods. Once households are recruited for the panel, they are contacted by e-mail for survey taking or panelists visit their online member page for survey taking (instead of being contacted by phone or postal mail). This allows surveys to be fielded very quickly and economically. In addition, this approach reduces the burden placed on respondents, since e-mail notification is less intrusive than telephone calls, and most respondents find answering Web questionnaires more interesting and engaging than being questioned by a telephone interviewer. Furthermore, respondents have the freedom to choose what time of day to participate in research.
KnowledgePanel Methodology Information
Complete and current information about KnowledgePanel sampling and recruitment methodology and design is available at: http://www.gfk.com/Documents/GfK-KnowledgePanel-Design-Summary.pdf
KnowledgePanel’s recruitment process is based on an Address Based Sampling (ABS) methodology for selecting panel members. This probability-based sampling methodology improves population coverage, and provides a more effective sampling infrastructure for recruitment of hard-to-reach individuals, such as young adults and those from various minority groups. It should be noted that under the ABS recruitment households without Internet connection are provided with a web-enabled device and free Internet service. After initially accepting the invitation to join the panel, participants are asked to complete a short demographic survey (the initial profile survey), answers to which allow efficient panel sampling and weighting for future surveys. Completion of the profile survey allows participants to become panel members and, as in the past, all respondents are provided the same privacy terms and confidentiality protections.
ABS Recruitment
Our recruitment protocol relies on probability-based sampling of addresses from the United States Postal Service’s Delivery Sequence File (DSF). The key advantage of the ABS methodology is that it allows sampling of almost all United States households. Regardless of household telephone status, all households can be reached and contacted through postal mail. Beginning in 2011, pre-identified ancillary information about addresses was used to construct and target households in the following four sampling strata:
1. Hispanic ages 18-24
2. Non-Hispanic ages 18-24
3. Hispanic ages 25+
4. Non-Hispanic ages 25+.
In 2012, a similar four-stratum design was implemented, with the ages changing to 18-29 and 30+ for both the Hispanic and non-Hispanic strata. As detailed below, specific adjustments are applied to compensate for any oversampling that is carried out to improve the demographic composition of the panel.
Randomly sampled addresses from the DSF are invited to join KnowledgePanel through a series of mailings, including an initial invitation letter, a reminder postcard, and a subsequent follow-up letter. Given that approximately 45% of the physical addresses can be matched to a corresponding landline telephone number, about 5 weeks after the initial mailing, telephone refusal-conversion calls are made to households for whom a telephone number was matched to the sampled address. Invited households can join the panel by: completing and mailing back a paper form in a postage-paid envelope, calling a toll-free hotline phone number maintained by GfK, or going to a designated GfK website and completing the recruitment form at the website.
Household Member Recruitment
For all recruitment efforts, during the initial recruitment survey, all household members are enumerated. Following enumeration, attempts are made to recruit every household member who is at least 13 years old to participate in KnowledgePanel surveys.
Survey Sampling from KnowledgePanel
Once panel members are recruited and profiled, they become eligible for selection for client surveys. In most cases, the specific survey sample represents an equal probability selection method (EPSEM) sample from the panel for general population surveys. Customized stratified random sampling based on profile data can also be conducted as required by the study design.
The general sampling rule is to assign no more than one survey per week to individual members. Allowing for rare exceptions during some weeks, this limits a member’s total assignments per month to four or six surveys. In certain cases, a survey sample calls for pre-screening, that is, members are drawn from a subsample of the panel (such as females, Republicans, grocery shoppers, etc.). In such cases, care is taken to ensure that all subsequent survey samples drawn that week are selected in such a way as to result in a sample that remains representative of the panel distributions.
For this survey, a nationally representative sample of U.S. adults (18 and older) who self-identify as Jewish by religion or background (“Jew by any other reason”) was invited to participate.
Survey Administration
Once assigned to a survey, members receive a notification email letting them know there is a new survey available for them to take. This email notification contains a link that sends them to the survey questionnaire. No login name or password is required. The field period depends on the client’s needs, and in this case was 16 days.
After three days, automatic email reminders are sent to all non-responding panel members in the sample. If email reminders do not generate a sufficient response, an automated telephone reminder call can be initiated. The usual protocol is to wait at least three to four days after the email reminder before calling. To assist panel members with their survey taking, each individual has a personalized “home page” that lists all the surveys that were assigned to that member and have yet to be completed.
GfK also operates an ongoing modest incentive program to encourage participation and create member loyalty. Members can enter special raffles or can be entered into special sweepstakes with both cash rewards and other prizes to be won. The typical survey commitment for panel members is one survey per week or four per month with duration of 10 to 15 minutes per survey.
Sample Weighting
As detailed above, significant resources and infrastructure are devoted to the recruitment process for the KnowledgePanel (KP) so that the resulting panel can properly represent the adult population of the US. This representation is not only achieved with respect to a broad set of geo-demographic distributions, but also hard-to-reach adults – such as those without landline telephone or Spanish language dominant individuals – are recruited in proper proportions as well. Consequently, the raw distribution of KP mirrors that of the US adults fairly closely, baring occasional disparities that may emerge for certain subgroups due to differential attrition rates among recruited panel members.
For selection of general population samples from KP, however, a patented methodology has been developed that ensures the resulting samples behave as EPSEM. Briefly, this methodology starts by weighting the entire KP to the benchmarks secured from the latest March supplement of the Current Population Survey (CPS) along several dimensions. This way, the weighted distribution of KP perfectly matches that of the US adults – even with respect to the above mentioned few dimensions where minor misalignments may result from differential attrition rates.
Study-Specific Post-Stratification Weights
Once the study sample has been selected and fielded, and all the survey data are edited and made final, design weights are calculated for any survey nonresponse as well as any under- or over-coverage imposed by the study-specific sample design (essentially, the obtained sample is weighted so as to conform to the panel universe of the target population). For this study, demographic and geographic distributions for the non-institutionalized, civilian population that self-identify as Jewish (by religion or background from KnowledgePanel) are used as benchmarks in this adjustment. Additionally, the obtained sample was weighted by denomination of Judaism, as provided by the Pew Research Center’s 2013 Survey of U.S. Jews.
The following benchmark distributions were utilized in this post-stratification adjustment:
• Age (18–34, 35–44, 45–59, 60+) by Gender (Male/Female)
• Race/Ethnicity (White, Non-White)
• Education (Less than High School/High School, Some College, Bachelor Degree or Higher)
• Census Region (Northeast, Midwest, South, West)
• Metropolitan Status (Metro Area, Non-Metro Area)
• Household income (under $25K, $25K to <$50K, $50K to <$75K, $75K+)
• Jewish by Religion (Yes, No)
• Denomination (Reform, Conservative, Orthodox, Reconstructionist, Just Jewish)
GfK then trimmed and scaled this weight to the sum of the total sample size.
The margin of sampling error, taking into account design effects related to weighting, was reported by GfK to be ±4.7%.
