B. Collection of Information Employing Statistical Methods
The sample universe for the Police-Public Contact Survey (PPCS) is all persons age 16 or older living in National Crime Victimization Survey (NCVS) interviewed households. The potential universe for the NCVS national sample is all persons age 12 or older in the more than 120 million U.S. households and persons 12 or older living in non-institutional group quarters (except crews of vessels, military in barracks, and those at domestic violence shelters or living quarters for victims of natural disasters). In 2022, the annual NCVS national sample is planned to be approximately 254,000 designated addresses located in 542 stratified Primary Sampling Units (PSUs) throughout the United States. From July 2022 through December 2022, when the 2022 PPCS is in the field, the NCVS national sample will include about 127,000 designated addresses.
Frame
The Master Address File (MAF) contains all addresses from the most recent decennial census, plus updates from the U.S. Postal Service, state and local address lists, and other address listing operations. The MAF is the frame for the target NCVS population. Every 10 years, the U.S. Census Bureau redesigns the samples for all of their continuing demographic surveys, including the NCVS. In general, the purpose of these redesigns is to capture population shifts measured by the most recent decennial census.
In 2015, the sample design based on the 2000 Census started to phase out, and the sample design based on the 2010 Census started to be phased in. The phase-in and phase-out of the sample designs started in January 2015 and continued through December 2017. Beginning in 2016, some PSUs were removed from the sample, some new PSUs were added to the sample, and some continuing PSUs that were selected for both the 2000 and 2010 designs remained in the sample. The 2018 NCVS was the first full year of the phased-in 2010 design where all PSUs and addresses were from the 2010 design. The new NCVS sample sizes are larger than in previous years to support state-level estimates in 22 states.
Rotating Panel Design
The NCVS uses a rotating panel design. The sample consists of seven groups for each month of enumeration. Each of these groups stays in the sample for an initial interview and six subsequent interviews, for a total of seven interviews for the typical household. During the course of the 6-month period when the PPCS will be administered, a full sample of seven rotation groups will be interviewed (one-sixth each month). One rotation group enters the sample for its first interview each month.
SAMPLE SELECTION
The sample design for the NCVS is a stratified, multi-stage cluster sample. Sample selection for the NCVS, and by default the PPCS, has three stages: the selection of PSUs, the selection of address units within sample PSUs, and the determination of persons and households from those addresses to be included in the sample.
Stage 1. Defining and Selecting PSUs
Defining PSUs – Formation of PSUs begins with listing counties and independent cities in the target area. For the NCVS, the target area is all 50 states and the District of Columbia. The PSUs comprising the first stage of the sample are formed from counties or groups of adjacent counties based upon data from the most recent decennial census and the American Community Survey (ACS). Counties are either grouped with one or more contiguous counties to form PSUs or are PSUs all by themselves. For counties that are grouped, the groupings are based on certain characteristics such as total land area, current and projected population counts, large metropolitan areas, and potential natural barriers such as rivers and mountains. For the NCVS, decennial census counts, ACS estimates, and administrative crime data drawn from the FBI’s Uniform Crime Reporting Program are also used to stratify the PSUs. The resulting county groupings are called PSUs.
After the PSUs are formed, the large PSUs and those in large urban areas are designated self-representing (SR). The smaller PSUs are designated non-self-representing (NSR). Determining which PSUs are considered small and which are considered large depends on the survey’s SR population cutoff, whether estimates are desired for the state, and the size of the metropolitan statistical area that contains the PSU.
Stratifying PSUs – For the 2010 design, the NSR PSUs are grouped with similar NSR PSUs within states to form strata. Each SR PSU forms its own stratum. The data used for grouping the PSUs are also based on decennial census demographic data, ACS data, and administrative crime data. NSR PSUs are grouped to be as similar or homogeneous as possible. Just as the SR PSUs must be large enough to support a full workload, so must each NSR strata. The most efficient stratification scheme is determined by minimizing the variance both between and within PSUs.
Selecting PSUs – The SR PSUs are automatically selected for sample or “selected with certainty.” NSR PSUs are sampled with probability proportional to the population size using a linear programming algorithm. One PSU is selected from each NSR stratum. The 2010 design NCVS sample includes 339 SR PSUs and 203 NSR PSUs. PSUs are defined, stratified, and selected once every 10 years. The 2010 design sample PSUs were sampled using population data from the 2010 Census.
Stage 2. Preparing Frame and Sampling within PSUs
Frame Determination – The 2010 sample design selects its sample from two dynamic address-based sampling frames, one for housing units and one for group quarters. Both frames are based upon the MAF, which is a national inventory of addresses. The MAF is continually updated by various U.S. Census Bureau programs and external sources. New housing units are added to the MAF, and therefore the NCVS sampling frame, through semiannual updates from a variety of address sources, including the U.S. Postal Service Delivery Sequence File, local government files, and field listing operations.
In the 2010 design, each address in the country was assigned to the sampling frame based on the type of living quarters. Two types of living quarters are defined in the decennial census. The first type is a housing unit (HU). An HU is a group of rooms or a single room occupied as separate living quarters or intended for occupancy as separate living quarters. An HU may be occupied by a family or one person, as well as by two or more unrelated persons who share the living quarters.
The second type of living quarters are group quarters (GQ). GQs are living quarters where residents share common facilities or receive formally authorized care. About 3% of the population counted in the 2010 Census resided in GQs. Of those, less than half resided in non-institutionalized GQs. About 97% of the population counted in the 2010 Census lived in HUs.
Within-PSU Sampling – All of the U.S. Census Bureau’s continuing demographic surveys, including the NCVS, are sampled together. This procedure takes advantage of updates from the January MAF delivery and ACS data. This within-PSU selection occurs every year for HUs and every three years for GQs.
Selection of samples is done sequentially, one survey at a time. Each survey determines how the unit addresses within the frame should be sorted prior to sampling. For the NCVS, each frame is sorted by geographic variables. A systematic sampling procedure is used to select addresses from each frame. A skeleton sample is also selected in every PSU. Every 6 months, new addresses on the MAF are matched to the skeleton frame. The skeleton frame allows the sample to be refreshed with new addresses and thereby reduces the risk of under-coverage errors due to an outdated frame.
Addresses selected for a survey are removed from the frames, leaving an unbiased or clean universe behind for the next survey that is subsequently sampled. By leaving a clean universe for the next survey, duplication of addresses across surveys is avoided. This is done to help preserve response rates by ensuring that no unit falls into more than one survey sample.
Stage 3. Persons within Sample Addresses
The last stage of sampling is done during initial contact of the sample address during the data collection phase. The NCVS has procedures to determine who lives in the sample unit, and a household roster is completed with names and other demographic information. If someone moves out of (or into) the household during the interviewing cycle, he or she is removed from (or added to) the roster. For the PPCS, if the address is a residence and the occupants agree to participate, then an attempt is made to interview every person age 16 or older who lives at the resident address and completes the NCVS-1.
The expected NCVS sample size for July 2022 through December 2022 is 127,000 households. Approximately 23,757 persons a month, age 16 and older, in these households will be eligible to be interviewed for the supplement during the PPCS administration, for a total of 142,545 possible interviews. Generally, interviewers can obtain PPCS interviews with approximately 84% of the PPCS-eligible household members in occupied units in the sample in any given month. A total of 119,880 persons age 16 and older are expected to be interviewed for the PPCS during the 6-month collection period.
State Samples
Beginning in January 2016, BJS and the U.S. Census Bureau increased and reallocated the existing national sample in the 22 most populous states. The states receiving a sample boost include Arizona, California, Colorado, Florida, Georgia, Illinois, Indiana, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Tennessee, Texas, Virginia, Washington, and Wisconsin. In 2017, each of these 22 states had a population greater than 5 million persons, and in total these 22 states comprised 79% of the U.S. population.1 The underlying assumption of the subnational sample design is that 3 years of data will be needed to produce precise estimates of violent crime, which is experienced by about 1% of the population. Sample sizes in the remaining 28 states and the District of Columbia were determined to ensure full representation and unbiased estimates at the national level. For the 2010 design, unlike the 2000 sample design, no strata cross state boundaries, and all 50 states and the District of Columbia have at least one sampled PSU.
Weighting and Estimation
The purpose of the PPCS is to make inferences about police-public contacts of the population age 16 or older in the United States. Before such inferences can be drawn, it is necessary to adjust, or weight, the sample of people to ensure it is similar to the entire population in this age group. The PPCS weights are a combination of household-level and person-level adjustment factors. Household and person respondents from the NCVS sample are adjusted on a biannual basis to represent the U.S. population age 12 or older. For the PPCS, the population is restricted to persons 16 or older.
NCVS household and person weights are first adjusted to account for any subsampling that occurs within large GQs. The NCVS nonresponse weighting adjustment then allocates the sampling weights of nonresponding households and persons to respondents with similar characteristics. Additional factors are then applied to correct for the differences between the sample distributions of age, race, Hispanic origin, and sex and the population distributions of these characteristics. The resulting weights are assigned to all interviewed households and persons in the NCVS file.
PPCS weighting begins with the NCVS final person weight, which is then multiplied by a PPCS noninterview adjustment factor. PPCS noninterview adjustment factors are computed by distributing the weights of PPCS noninterviews to the weights of the PPCS interviews, with adjustment cells determined by age, race, Hispanic origin, and sex. The result is a PPCS person-level weight that can be used for producing estimates from the PPCS variables.
Variance Estimates
The NCVS and PPCS estimates come from a sample, so they may differ from figures using an enumeration of the entire population using the same questionnaires, instructions, and enumerators. For a given estimator, the average squared difference between estimates based on repeated samples and the estimate that would result if the sample were to include the entire population is known as sampling error.2 The sampling error quantifies the amount of uncertainty in an estimate as a result of selecting a sample.
Variance estimates can be derived using direct estimation or generalized variance functions (GVFs). Both methods are used to produce PPCS statistical estimates. Replication methods provide estimates of variance for a wide variety of designs using probability sampling even when complex estimation procedures are used. This method requires sample selection, data collection, and estimation procedures to be carried out (i.e., replicated) several times. In addition, the U.S. Census Bureau produces parameters for GVFs that estimate the variance of any crime count estimate based on the value of the estimate. To do this, estimates and their relative variance are fit to a regression model using an iterative weighted least squares procedure where the weight is the inverse of the square of the predicted relative variance.
The PPCS is designed to calculate national estimates of contact between the police and the public for the target population—the noninstitutional resident population age 16 years and older living in NCVS households. The PPCS will be administered to all NCVS respondents age 16 or older during from July 2022 through December 2022.
From July 2022 through December 2022, the PPCS will be administered to approximately 127,000 designated households. The NCVS uses a rotating sample that consists of seven groups for each month of enumeration. Each HU selected for the NCVS remains in the sample for 3 years, with each of seven interviews taking place at 6-month intervals.
The NCVS-500 (Control Card) is used to complete a household roster with names and other demographic information of the household members. For some demographic questions that are asked directly of respondents, flashcards are used, such as for education, race, Hispanic origin, employment, sexual orientation, gender identity, and household income.
Respondents are asked to report victimization experiences occurring in the 6 months preceding the month of interview. The NCVS Crime Screener instrument (NCVS-1) is asked of all respondents age 12 years or older in the household and is used to ascertain whether the respondent has experienced a personal crime victimization during the prior 6 months and is therefore eligible to be administered the NCVS Crime Incident Report instrument (NCVS-2). The NCVS-1 collects the basic information needed to determine whether the respondent experienced a crime victimization (rape or other sexual assault, robbery, aggravated or simple assault, personal larceny, burglary, motor vehicle theft, or other types of household theft).
When a respondent reports an eligible personal victimization, the NCVS-2 is then administered to collect detailed information about the crime incident. The NCVS-2 is administered for each incident the respondent reports. For each victimization incident, the NCVS-2 collects information about the offender (e.g., sex, race, Hispanic origin, age, and victim-offender relationship), characteristics of the crime (including time and place of occurrence, use of weapons, nature of injury, and economic consequences), whether the crime was reported to police, reasons the crime was or was not reported, and victim experiences with the criminal justice system. Clearance for the core NCVS forms and materials including the NCVS-500, NCVS-1, and NCVS-2 are requested through a separate OMB request (OMB Control No: 1121-0111).
At each interview period, the interviewer completes or updates the household composition component of the NCVS interview and asks the crime screener questions (NCVS-1) for each household member age 12 or older.3 The interviewer then completes a crime incident report (NCVS-2) for each reported crime incident identified in the crime screener. Once the NCVS interview is completed (i.e., nonvictims responded to all NCVS-1 screening questions or victims completed all necessary NCVS-2 incident reports), the interviewer administers the PPCS questionnaire to persons age 16 or older.
Until 2015, respondents who completed the NCVS interview in a language other than English were ineligible for participation in the PPCS. This resulted in nonresponse bias among Hispanics in particular. Additionally, given the potential issues related to contact between police and non-English speaking residents, the inclusion of non-English speakers was an important change to the 2015 collection, which continued in 2018 and 2020 and will continue in 2022. U.S. Census Bureau field representatives will use “on-the-fly” translation (there is no “official” translation of the PPCS) to administer the PPCS to respondents for whom the NCVS was translated. This is standard practice, as the core NCVS and most other NCVS supplements also use “on-the-fly” translation.
The complete 2022 PPCS instrument is included for review as Attachment 3. For details on testing of the instrument, see Section 4.
If the interview occurs during the first contact with a household that is new to the sample, the interview is typically conducted in person. Households that have been previously interviewed and are in their second through seventh interview can be interviewed by telephone whenever possible. A little over half (56%) of all interviews conducted each month are by telephone.
PPCS Collection
The PPCS is designed to calculate national and state estimates of public contact with the police for the target population—all persons age 16 or older living in NCVS households during the sample period.
Eligible respondents for the PPCS include residents 16 years of age or older who successfully completed their NCVS interview by self-response. NCVS proxy interviews are considered a response for NCVS but are not eligible for PPCS and are, therefore, considered as PPCS nonresponse.
In the spring of 2020, the COVID-19 pandemic drastically altered 2020 interviewing procedures for the NCVS and PPCS. Effective March 19, 2020, interviews via personal visit were suspended for the remainder of 2020 PPCS data collection. Since incoming (first interview) NCVS cases are typically interviewed via personal visit, these cases were removed from the sample for the remaining months of PPCS data collection (April 2020 through June 2020).
Contact Strategy
Contact materials focus on the NCVS in general and do not specifically reference the PPCS. The U.S. Census Bureau mails notifications to households prior to data collection, interviewers contact households for the first time in person, and interviewers conduct nonresponse follow-up. The U.S. Census Bureau mails an introductory letter (NCVS-572(L)) or continuing household letter (NCVS-573(L)) explaining the NCVS to the household before the interviewer's visit or call (Attachments 6 and 7). When they go to a household, the interviewers carry cards identifying them as U.S. Census Bureau employees. Potential respondents are assured that their answers will be held in confidence and are used for statistical purposes. For respondents who have questions about the NCVS, interviewers provide a brochure and can also reference information in their Information Card Booklet that contains information such as uses of NCVS data and frequently asked questions and answers. After interviews are completed at each enumeration period, the U.S. Census Bureau mails thank-you letters to the household. All forms and materials used for contact with the household have been previously approved by OMB (OMB NO: 1121-0111).
The U.S. Census Bureau trains interviewers to obtain respondent cooperation and instructs them to make repeated attempts to contact respondents and complete all interviews. The interviewer obtains demographic characteristics of noninterview persons for use in the adjustment for nonresponse. PPCS response rates are monitored monthly and compared to the previous month’s average to ensure their reasonableness.
As part of their job, interviewers are instructed to keep noninterviews, or nonresponse from a household or persons within a household, to a minimum. Household nonresponse occurs when an interviewer finds an eligible household but obtains no interviews. Person nonresponse occurs when an interview is obtained from at least one household member, but an interview is not obtained from one or more other eligible persons in that household. Maintaining a high response rate involves the interviewer’s ability to enlist cooperation from all kinds of people and contact households when people are most likely to be home. As part of their initial training, interviewers are exposed to ways in which they can persuade respondents to participate, as well as strategies to use to avoid refusals. Furthermore, the U.S. Census Bureau staff makes every effort to help interviewers maintain high participation by suggesting ways to obtain an interview and by making sure that sample units reported as noninterviews are, in fact, noninterviews. Also, survey procedures permit sending a letter to a reluctant respondent as soon as a new refusal is reported by the interviewer to encourage their participation and to reiterate the importance of the survey and their response.
Interviewer Training
Training for NCVS interviewers consists of classroom and on-the-job training. Initial training for interviewers consists of a full-day of pre-classroom self-study, 4 days of classroom training, post-classroom self-study, and on-the-job observation and training. Initial training includes topics such as protecting respondent confidentiality, gaining respondent cooperation, answering respondent questions, proper survey administration, use of systems to collect and transmit survey data, NCVS concepts and definitions, and completing simulated practice NCVS interviews. The NCVS procedures and concepts taught in initial training are also regularly reinforced for experienced NCVS interviewers. This information is received via monthly written communications, ongoing feedback from observations of interviews by supervisors, and monthly performance and data quality feedback reports.
NCVS interviewers also receive specific training on the PPCS (see Attachment 8) including eligibility, the organization of the PPCS interview, content of the survey questionnaire, addressing potential respondent questions, and internal check items that are in place to help the interviewer ensure that the respondent is being asked the appropriate questions and follow up when clarification is needed. Interviewers receive a self-study training manual that they are required to read, and they must complete a Final Review Exercise to verify their knowledge of the concepts presented in the self-study training manual. The PPCS training materials are distributed to interviewers electronically on their U.S. Census Bureau laptops approximately a month before the supplement goes into the field.
Monitoring Interviewers
In addition to the above procedures used to ensure high participation rates, the U.S. Census Bureau implements additional performance measures for interviewers based on data quality standards. Interviewers are trained and assessed on administering the NCVS-1, NCVS-2, and PPCS exactly as worded to ensure the uniformity of data collection, completing interviews in an appropriate amount of time (not rushing through them), and keeping item nonresponse and “don’t know” responses to a minimum. The U.S. Census Bureau also uses quality control methods to ensure that accurate data are collected. Interviewers are continually monitored by their regional office to assess whether performance and response rate standards are being met and corrective action is taken to assist and discipline interviewers who are not meeting the standards.
Reinterview is a major feature of both the quality assurance (QA) and the missed crimes estimation program. The NCVS QA reinterview uses two approaches: random and supplemental (supervisor discretion) to validate interviewer performance. The missed crimes estimation program uses the data from the QA program to estimate household- and person-level missed crimes. The random reinterview approach consists of selecting a sample of each interviewer’s work to review over the data collection cycle. The supplemental approach allows supervisors to identify additional interviewers or cases for review throughout the cycle. Reinterview requires that a supervisor or experienced interviewer re-contact respondents at a sample of previously interviewed households. Reinterviewers verify that the original interviewer contacted the correct sample unit, determined the correct household composition, and classified noninterview households correctly. Reinterviewers also verify the household roster and tenure, ensure specific questions are covered, and re-ask a subset of the crime screener questions from the core NCVS.
Another component of the data quality program is monthly feedback. In 2011, the U.S. Census Bureau implemented a series of field performance and data quality indicators. Previously, high response rates were the primary measure of interviewer performance. The data quality indicators are tracked through the U.S. Census Bureau’s expanded Performance and Data Analysis tool, and monthly reports provided to the field. Under the revised performance structure, interviewers are monitored on the following:
response rates (household, person, and the current supplement in the field)
time stamps (the time it takes to administer the screener questions on the NCVS-1 or the crime incident questions on the NCVS-2)
overnight starts (interviews conducted very late at night or very early in the morning)
late starts (cases not started until the 15th or later in the interview month)
absence of contact history records (cases missing records of contact attempts with the household and/or persons within the household)
quality of crime incidents (changes made to the location, presence, or theft data items on the NCVS-2 during post-processing coding operations).
Noncompliance with these indicators results in supervisor notification and follow-up with the interviewer. The follow-up activity may include simple points of clarification (e.g., the respondent works nights and is only available in the early morning for an interview), additional interviewer training, or removal of the interviewer from the survey.
Every effort has been made to make the survey materials clear and straightforward. The PPCS instrument has been designed to make collection of the data as concise and easy for the respondent as possible. The PPCS questions have been cognitively tested to ensure that they are easily understood by most respondents.
Nonresponse and Response Rates
Interviewers can obtain NCVS interviews with about 83% of household members in 71% of the occupied units in the sample in a given month. The interviewers are trained to make repeated attempts at contacting respondents and to complete interviews with all eligible household members. Annually, the U.S. Census Bureau conducts complete analyses of nonresponse. The interviewers obtain demographic characteristics of noninterview persons for use in the adjustment for nonresponse. As was done for previous iterations of the PPCS, the U.S. Census Bureau plans to report nonresponse and response rates, respondent and nonrespondent distribution estimates, and proxy nonresponse bias estimates for various subgroups for the 2022 PPCS. Should the analyses reveal evidence of nonresponse bias, BJS will work with the U.S. Census Bureau to assess the impact on estimates and ways to adjust the weights accordingly.
The overall 2020 PPCS weighted response rate was 50.8%, which caused concern of potential bias in the PPCS estimates. The nonresponse bias analysis found significant differences in response rates and in respondent and nonrespondent distributions between different demographic subgroups. However, following nonresponse weighting adjustments, there was no evidence of nonresponse bias in any of the police contact key estimates.
All survey questions were tested during the previous collections and are known to be easily understood and answered. Since 1996, the PPCS has been administered nine times periodically. In May, June, and July 1996, BJS supplemented the NCVS with a pilot test of the first PPCS instrument designed to collect answers from respondents to a series of questions about the nature and consequences of their face-to-face interactions with the police. Following the initial PPCS implementation, BJS redesigned the instrument to accomplish a number of objectives not addressed by the original survey instrument, particularly with respect to broadening the range of participants describing their interactions with the police.
The PPCS was again conducted as a supplement to the NCVS between July 1, 1999 and December 31, 1999. An improved version of the survey instrument that included a new and more detailed set of questions about traffic stops by police was fielded with a national sample nearly 15 times as large as the pretest sample in 1996. That same PPCS instrument was then repeated as a supplement to the NCVS in 2002, 2005, and 2008 and to about 15% of the sample in 2011.
In 2011, BJS redesigned the PPCS with the goals of providing stronger cues for respondents by using more specific questions about types of contact, gathering more data on voluntary contacts with police, improving the measurement of street stops (also known as “stop and frisks”), and collecting data on the interactions and behaviors between residents and police. The 2011 PPCS was administered to a split sample of respondents (85% were administered the 2011 instrument, while 15% were administered the prior year’s instrument) to test the impact of instrument changes on the rate of contact with police and to allow for the continued examination of trends in police contact over time. BJS produced a technical report that provides trends in police contact from 1999 to 2011, adjusting for changes to the 2011 instrument where possible.4 Initial findings suggested that the revised screener resulted in a statistically significant increase in the rate of contact. However, once the prior year rates of contact were adjusted to account for the change, there was no statistically significant change in the rate of contact from 2008 to 2011.
While the revised instrument provided valuable new data on the nature of street stops and resident requests for assistance from police, the analysis also revealed that the changes to the instrument resulted in an inability to generate an overall rate of use of force across all police contacts. Additionally, the new screener created uncertainty about how contacts resulting in arrest were classified by respondents.
Given the issues with the 2011 instrument, BJS revised the 2011 instrument for the 2015 data collection to include a more extensive screener section to better capture the experiences of the public and direct the respondent toward relevant and salient questions to elicit as much information as possible regarding the contact with police. Other changes in 2015 included questions about the number of contacts so that BJS could generate an incident rate; administration of use-of-force questions to all respondents, regardless of the type of contact experienced during their most recent encounter with police; and administration of the supplement to NCVS respondents who received the NCVS in a language other than English.
In addition, BJS made three substantive improvements to the PPCS instrument prior to the 2018 administration. The first was the addition of a verification question following multiple screener items that ask about various types of contact with the police. The new verification question allowed interviewers to confirm they accurately understood all incidents reported. The other two substantive changes came as a result of the comment period for the 2015 PPCS. BJS received recommendations to include questions to collect data on perceptions of police behavior toward LGBTQ persons. Given the small sample sizes that would be associated with these questions, BJS instead broadened the purview and added two questions—one aiming to address perceptions of verbal and/or sexual harassment by police and one aiming to address perceptions that police behaviors were motivated by prejudice or bias against the respondent. Several minor instrument changes were implemented as a result of previous results and cognitive testing.
Given the adjustments to the screener, in particular, cognitive testing on the 2018 PPCS instrument was conducted by the Center for Survey Measurement at the U.S. Census Bureau, under their generic clearance for questionnaire pretesting research (OMB number 0607-0725). It focused on the PPCS screener and the classification and enumeration of different types of police contact, as well as the new questions. The testing was conducted in four rounds between June and November 2017. In total, 50 individuals were interviewed: 15 in each of the first two rounds and 10 each in the third and fourth rounds.
Initial rounds of testing indicated that respondents struggled to correctly classify some of their contacts in response to the appropriate screener question. These errors occurred more frequently with questions about self-initiated contacts. Respondents were not always able to make clear distinctions in how they classified crimes, disturbances, suspicious activity, non-crime emergencies, and non-emergency assistance. As a result, they often reported the same incident in response to multiple questions. This occurred because some respondents were not sure which item was a more appropriate fit and because some respondents were not sure if a better-fitting question was going to be asked or if the current item was their best chance to report the contact. In addition to difficulty classifying the type of contact they experienced, many respondents experienced recall issues, forgetting about contacts or the number of contacts until discussing their experiences with the interviewer and responding to probing questions as part of the cognitive interview.
Due to the recurring issues experienced by respondents, several global changes were made to the questionnaire throughout testing. Before being asked the screener questions about self-initiated contacts, introductory text was added explaining that the interviewer will ask about five reasons why the respondent may have contacted the police in the past 12 months. The intro text also explains that respondents can say yes to more than one reason, but should choose the reason that best fits why they contacted the police on each occasion. Similar intro text was added before the police-initiated contact section of the screener, with text explaining that the respondent will be asked about four reasons why the police may have initiated contact with them.
A verification question was also added after the completion of the screener questions asking about the various types of police contacts. The verification question explains that the interviewer is going to read a list of what the interviewer recorded to make sure everything is correct and explains that each contact should only be counted once. The interviewer then lists the types of contacts and number of each type of contact the respondent reported and asks if everything is correct. If the respondent says it is not correct, the interviewer asks what is not correct. Once this verification question is asked and information is corrected, if respondents reported more than one contact, they are asked which of those contacts just discussed occurred most recently to determine the appropriate path for the survey. Later rounds of cognitive testing revealed that the new verification item helped identify contacts that were double-reported while also verifying that respondent-reported contacts were correctly classified under the most applicable type of police contact.
While the focus was on the screener questions, the entirety of the questionnaire was cognitively tested. Overall, the survey sections after the screener performed well and caused few issues for respondents. Several additional minor instrument changes were implemented as a result of previous results and cognitive testing. However, because most of the questions on the 2018 instrument had already been used or tested previously, there were few major changes to the instrument as a result of the testing.
The 2020 PPCS instrument maintained all of the questions from the 2018 PPCS and reintroduced one question that was not asked in 2018 but was asked in years prior. The reintroduced question was asked of residents who reported that their most recent contact with police was initiated by the police. These residents were asked if at any time during the contact, they a) disobeyed or interfered with the officer(s); b) tried to get away; c) pushed, grabbed, or hit the officer(s); d) resisted being handcuffed, arrested, or searched; e) complained to the officer(s); f) argued with the officer(s); g) cursed at, insulted, or verbally threatened the officer(s); or h) physically did anything else. This question was previously tested for other survey years, and all other questions on the 2022 PPCS were tested prior to the 2018 administration. Therefore, no cognitive testing occurred for the 2022 PPCS.
BJS takes responsibility for the overall design and management of the activities described in this submission, including developing study protocols, sampling procedures, the questionnaire, and overseeing the conduct of the studies and analysis of the data by contractors.
The U.S. Census Bureau will collect all information. Meagan Meuchel is the survey director, National Crime Victimization Survey at the U.S. Census Bureau and manages and coordinates the NCVS and its supplements. David Hornick of the Demographic Statistical Methods Division of the U.S. Census Bureau oversees the statistical aspects of the supplement. BJS and U.S. Census Bureau staff contacts for the PPCS include –
BJS Staff: all staff located at 810 7th Street, NW Washington, DC 20531 |
U.S. Census Bureau Staff: all staff located at 4600 Silver Hill Road Suitland, MD 20746 |
Heather Brotsos Chief Victimization Statistics Unit |
Meagan Meuchel NCVS Survey Director Associate Directorate for Demographic Programs – Survey Operations |
Elizabeth Davis Statistician Law
Enforcement Statistics |
Megan Ruhnke NCVS Assistant Survey Director Associate Directorate for Demographic Programs – Survey Operations |
Susannah N. Tapp Statistician Victimization Statistics Unit |
Chris Seamands NCVS Assistant Survey Director Associate Directorate for Demographic Programs – Survey Operations |
|
Scott Raudabaugh Branch Chief, Crime Surveys Programming & Population Support Demographic Surveys Division |
|
David Hornick Lead Scientist Demographic Statistical Methods Division |
Attachment 1: Language regarding data on use of excessive force (34 U.S.C. § 12602)
Attachment 2: BJS authorizing statute; 34 U.S.C. §§ 10131 and 10132
Attachment 3: 2022 PPCS questionnaire
Attachment 4: Selected nonfederal publications using PPCS data
Attachment 5: Public comments received in response to 60-day notice
Attachment 6: Incoming household letter from the U.S. Census Bureau (NCVS-572(L))
Attachment 7: Continuing household letter from the U.S. Census Bureau (NCVS-573(L))
Attachment 8: 2020 PPCS training material
1 Table 1. Annual Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2010 to July 1, 2017 (NST-EST2017-01). Source: U.S. Census Bureau, Population Division. Release Date: December 2017.
2 Everitt, B.S., and Skrondal, A. (2010). The Cambridge Dictionary of Statistics, Fourth Edition. Retrieved from http://www.stewartschultz.com/statistics/books/Cambridge%20Dictionary%20Statistics%204th.pdf.
3 About 6% of NCVS interviews are conducted by proxy. NCVS proxy interviewees are not eligible to complete the PPCS. Given the nature of the questions, BJS determined that proxy respondents would have difficulty describing the details of contacts between police and the sampled respondents. For instance, respondents are asked whether they felt the force was excessive; a proxy interviewee would not know how the sampled respondent felt about the use of force.
4 Police-Public Contact Survey: Assessment and Recommendations for Producing Trend Estimates after 2011 Questionnaire Redesign (NCJ 250485, BJS, April 2017)
| File Type | application/vnd.openxmlformats-officedocument.wordprocessingml.document |
| Author | Langton, Lynn |
| File Modified | 0000-00-00 |
| File Created | 2022-02-16 |