Glossary of Terms

Response Rate 1 (RR1): the number of complete interviews divided by the number of interviews (complete and partial), the number of non-interviews (refusal, break-offs, non-contact and others), and number of cases of unknown eligibility. Response Rate 2 (RR2): the number of complete and partial interviews divided by the number of interviews (complete and partial), the number of non-interviews (refusal, break-offs, non-contact and others), and number of cases of unknown eligibility. Response Rate 3 (RR3): the number of complete interviews divided by the number of interviews (complete and partial), the number of non-interviews (refusal, break-offs, non-contact and others), and an estimate of the proportion of cases of unknown eligibility that are actually eligible. Response Rate 4 (RR4): the number of complete and partial interviews divided by the number of interviews (complete and partial), the number of non-interviews (refusal, break-offs, non-contact and others), and an estimate of the proportion of cases of unknown eligibility that are actually eligible. Response Rate 5 (RR5): a special case of RR3 in which either the proportion of eligible cases among the cases of unknown eligibility is assumed to be zero or there are no cases of unknown eligibility. Response Rate 6 (RR6): a special case of RR4 in which either the proportion of eligible cases among the cases of unknown eligibility is assumed to be zero or there are no cases of unknown eligibility.

A short description of the types of substantive questions in the questionnaire. Demographics and survey-organization defined variables, like date of interview, are not described.

A group of persons (or any other units of analysis) that have some characteristics in common without necessarily having any other connection to each other. For example, Teachers in the U.S. , Internet-users, or Voters.

The Center’s online catalog of studies.

A presentation of survey results with many crosstab tables that indicate how different types of respondents responded to each survey question.

The dates of interviewing.

The analysis of the relationship between an independent and dependent variable. (e.g. a cross tabulation showing presidential approval for men and women separately).

Used to search the Roper database, Boolean logic uses the terms "and," "or," and "not' as connectors between keywords or phrases to narrow the results of keyword searches.

The percent of respondents who start the survey but do not finish it.

This occurs when an interviewer attempts to reach a potential survey respondent by phone after failing to reach them previously. Most telephone surveys will set a maximum number of callbacks and continuing attempting to reach the respondent until that number has been reached.

A mode of survey data collection in which an in-person interviewer uses a computer to administer the survey and record responses.

A mode of survey data collection in which a telephone interviewer uses a computer to administer the survey and record responses.

A technique of adjusting weights on respondents in a survey in which the weight applied to each subgroup in the dataset (e.g. men over the age of 55) is calculated based on the relevant distribution of the target population.

A census is often similar to a survey, with the difference that the census collects data from all members of the population while the survey is limited to a sample.

Redirecting an online respondent to another survey at the end of a completed survey

A reference intended to uniquely identify the study/dataset used in research. Mutiple citations formats are available on the Cite Study tab for each study in the archive, and citations are also available for individual questions.

A list of the variables and how they have been coded in a survey. Every polling organization has its own methods for coding, so every codebook will look a little different.

The process of translating data (respondents' answers to questions) into a format that can be read and manipulated by a computer and later analyzed by the survey researcher. For example, a female respondent answers the following question: Are you: a) Democrat b) Republican c) Independent d) Don't Know When this question is coded later, it may look like this: Sex: 1=Male 2=Female Party: 1=Democrat 2= Republican 3= Independent 8=Don't Know 9=No Answer/Refused, and coded accordingly.

Method by which data were collected, such as telephone, in-person, online, etc.

A continuous variable is a variable that can be expressed by an infinite number of measures. For survey purposes, they are usually measured on an interval or ratio scale. (i.e. time, speed, weight - since these may be broken down into an infinite number of smaller parts.)

A table which shows the influence of an independent variable (located in the column) on a dependent variable (located in the row.)(e.g. a table showing how income is related to the likelihood of voting for a certain candidate).

A mode of survey data collection in which the respondent completes the survey using computer technology with little or no assistance from an administrator. CSAQ applications include online surveys.

This is a process where the researcher searches or "digs" through data-bases for information that may validate his/her own work or inspire ideas for new projects.

The individual-level results of a survey, conceptualized as a table or "matrix" where the rows contain values for each individuals' coded responses. For example, a "1" on presidential approval might mean "approve" while a "2" might mean "disapprove." "Don'tknow" is often coded as "8" or "9". Datasets may be used for secondary analysis. The raw data. Each respondents responses to a question laid out in a table like form. Datasets consist of all of the information gathered during a survey which needs to be analyzed. Learning how to interpret the results is a key component to the survey process. * The individual-level results of a survey, conceptualized as a table or "matrix." The rows contain values for each individual's coded responses to the questions asked (contained in the columns.) * Below you can see part of the SPSS downloaded dataset for the results of the USVNS National Election 2000. Column 9, for example, shows the variable "pres", which stands for "presidential vote." In the "Values" column, a "1" was coded for Gore, "2" for Bush, etc. (The pop-up box shows the other Value Labels in that category.) * Statistical software is necessary to define, manipulate, and extract variables and cases within data files. * Small data files may also be analyzed within spreadsheet software such as Excel.

This is a reference tool used by Roper Center staff {Link to page for Roper Center Staff} and is not necessarily the date of a survey's first public release. When no release date exists, the last day of the interviewing period is used.

In research, a dependent variable (also called the output variable) is the variable that is being measured in an experiment. It "depends" on other factors. For example, if the research question is "Does education level have an effect on annual income?" income is the dependent variable; the question is asking whether income "depends" on education level.

A type of (close-ended) question which has two answer choices. e.g. Are you: a) Female b) Male

A discrete (also known as categorical or nominal) variable is one that has two or more categories with no intrinsic order. For example, Sex, Hair color, and Favorite radio station. You can assign these variables to a category, but they have no order from highest to lowest. Therefore, you can't find "the average" of hair color. (See ordinal variable)

A set of codes or categories used by survey researchers to document the ultimate outcome of contact attempts on individual cases in a survey sample.

The DOI, or Digitial Object Identifier, a permanent identifier for the study

A survey that is conducted on voters immediately after exiting a polling station, asking them how they voted. Exit polls are intended to allow for better understanding of voting behavior of different groups in the electorate and drivers of vote choice.

When applicable, the name of the organization that commissioned the survey. If the same organization funded, designed, and fielded a poll, no sponsor is listed.

A type of ratings scale where respondents are asked to gauge their attitudes about a particular topic or person. For example, ratings between 50 degrees and 100 degrees mean that you feel favorable and warm toward a person. Ratings between 0 degrees and 50 degrees mean that you Don'tfeel favorable toward the person. You would rate the person at the 50 degree mark if you Don'tfeel particularly warm or cold toward the person. The National Election Studies (NES) has often used this rating scale for questions about presidential candidates.

A type of question used on surveys in order to determine which subsequent (if any) questions to ask.

A small group selected from a wider population that is led by a moderator in an open discussion about the research topic. While there are many different functions of a focus group, there are typically three reasons why a focus group is used in qualitative research. The information gathered from the group interaction is used: 1) to gain insights that will help generate data for the development of a survey 2) as a supplementary source in a study along with other methods of data-collecting; used in either a preliminary or follow-up stage of the research 3) in combination with other methods of interviewing for the research project. Focus groups are often used in the areas of market research and political opinion analysis.

The version of a questionnaire used in a survey. While online or telephone surveys often utilize split samples to test different wordings or to included more questions than would be manageable in a single questionnaire, printed surveys require more than one form of the questionnaire to be printed and distributed if the questions are giong to vary. Multiple forms of questionnaires were often used in early polling. Information about the forms in Roper polls can be found in the survey documentation.

The unique identifier assigned by the Roper Center to every question in the iPOLL database.

The geographic area from which data were collected.

The funding agency that provided grant support for the study.

Replacing missing values for a respondent in a dataset with corresponding values from a similar respondent. For instance, if a respondent failed to answer a specific question, their non-response would be replaced with the response given by another respondent who was similar to them with regard to other characteristics.

In research, an independent variable (also called experimental variable or predictor variable) is a variable that is measured for its effect on the dependent variable(s). As the independent variable changes, its effect on the dependent variable is observed by the researcher. For example, if the research question is "does education level have an effect on annual income?" education level is the independent variable.

A means of sampling or selecting people to participate in a survey that involves recruiting respondents at a particular public place or event. An intercept survey is usually administered by an in-person interviewer.

An interval variable is similar to an ordinal variable except that the intervals between the values of the categories are equidistant, or equally spaced. However, there is no meaningful "zero" point. For example, Age.

A data collection encounter in which one person (an interviewer) asks questions of another (a respondent). Interviews may be conducted face-to-face or by telephone.

The date range during which data was collected from respondents.

Interviewers can intentionally or unintentionally prompt respondents to reply in a particular manner. Characteristics like sex, race, age, physical appearance and behavior can have subtle or sometimes, obvious affects on respondents during the interview process. Some respondents may answer in a manner that they believe would please the interviewer. It is for this reason that survey firms seeking to interview special samples of the population will carefully select interviewers with like characteristics to conduct the survey.

The mode of interviewing: mail, telephone, in-person, online, etc.

The most comprehensive and up-to-date source for national public opinion data in the United States. Roper iPoll is a database and study catalog holding polling datasets, as well as a full-text question-level retrieval system. iPoll is designed so that users can locate, examine, and ultimately capture questions asked on national U.S. and state-level surveys on a variety of topics.

A technology that allows a computer to interact with humans through the use of voice and keypad input. IVR technology can replace a human interviewer in telephone surveys. IVR surveys are sometimes called "robocalls."

A special library collection of public opinion data from Japan. The archive includes over 1,000 reports containing full-question text and responses from surveys conducted in Japan from 1980 through 1995. These studies, done by the principal polling agencies in Japan, contain more than 20,000 survey questions and their corresponding responses.

A means of estimating whether a survey respondent is likely to vote in an election. Survey firms typically use questions about a respondent's past voting behavior and their intention to vote in future elections in order to identify respondents that are most likely to vote in an election, to increase the accuracy of electoral predictions based on surveys. Likely voter screens range widely in complexity, from single questions to multi-question indexes. Survey organizations often keep the elements of their likely voter model proprietary.

A widely used response format that allows for measuring typically qualitative attitudes into quantitative measures. For example, response options may include: "strongly agree", "agree", "disagree", "strongly disagree".

A statistic that captures the amount of random sampling error in a survey's results. Random sampling error is the difference between the values of the sample and the values of the population from which the sample is drawn. It is usually unknown but can be estimated.

The average. To calculate this, simply add up the values for each case and divide by the total number of cases. (e.g. If you want to find out the average number of hours you spend on the computer each week, simply add up your daily hours and divide them by seven.)

The middle score or measurement in a set of ranked scores or measurements.

The study of methods and research practices used in a field of study. In survey research, methodology refers to the study of different means of collecting and analyzing survey data.

The method or mode of interviewing: mail, telephone, in-person, online, etc.

A technique for selecting members of a given household for a survey. Interviewers ask to speak to the member of the household with the most recent birthday. This selection method is called quasi-random.

A sampling method using more than one stage in the process of gathering the sample. (e.g. You want to interview Missouri voters about their preferences in an upcoming election. However, you have limited resources in your ability to contact them. Therefore, you randomly select 30 voting districts in the state. From there, you randomly select towns. Within those towns, you randomly select neighborhoods. From the neighborhoods, you randomly select streets. and so on.)

The analysis of more than two variables simultaneously, for the purpose of determining the relationship between and/or among them. For example an issue by age and by sex.

The number of observed cases in a sample. In polling, N refers to the number of respondents.

A technique for selecting members of a given household for a survey. Interviewers ask to speak to the member of the household whose birthday is next.

An instance in which a survey respondent selected to participate in a survey cannot be reached. For instance, if a respondent is selected for an in-person survey based on their address, but is not at home when the interviewer visits the address, this would be considered a noncontact.

A type of sampling where samples are drawn utilizing non-random methods. In nonprobability sampling, all members of the universe do not have a known, non-zero probability of being sampled. Inferences about the target population should not be made based on such surveys unless methods, such as propensity-score weighting, have been put in place to adjust the results to better represent the total population, including those with a zero probability of being sampled. Non-probability sampling was standard in the United States before 1950, when U.S. polling organizations began to move to probability-based methods. In recent years, online polling utilizing non-probability sampling methods have become common. See also: quota sampling, river sampling.

A type of sampling where samples are drawn arbitrarily, without regard to scientific methods; and, therefore, should not be used to make statistical inferences about the target population. (i.e. "person on the street" samples)

An instance in which a survey respondent fails to complete a survey or answer a survey question. Systematic or non-random nonresponses can result in nonresponse bias.

A type of bias resulting from respondents failing to complete a survey or answer a specific survey question for systematic reasons. For instance, if younger respondents are less likely to complete a survey on political ideology than older ones, survey results may be biased in a particular direction.

One survey that collects responses on a wide range of questions for multiple individuals or organizations. Pooling questions to field an omnibus survey may lower costs.

A sample of respondents who have agreed to complete surveys online. Survey firms use online panels to quickly obtain responses from large groups of respondents. Online panels can utilize probability-based or non-probability-based sampling procedures. Probability-based online panels recruit panelists using traditional probability-based methods, like RDD telephone surveys, then provide internet access to those who require it. Non-probability-based online panels recruit their respondents through a variety of methods, including online ads.

An ordinal variable is similar to a discrete variable; however, the difference is that there is a clear ordering of the variables from low to high. For example, "Education." There is an order as well as a value from low to high when it comes to measuring years of education. We can code the variable as follows: "1"=Less than High School Graduate; "2"=H.S. Grad/Some College; "3" =College Graduate; "4" =Post Graduate or more We know that there is an order from low to high in this case, but the size of the difference between each of the categories is not necessarily equidistant from one to the next. (If the difference between each of the categories were equally spaced, the variable would be an interval variable.)

Searches organizations associated with surveys, including both external sponsors and survey field organizations.

An extreme value of a variable in a dataset. This extreme value can distort the results of your survey if you're dependent solely on the mean statistic for analysis. i.e. Here is a list of test scores: 90, 87, 99, 95, 85, 43, 91. The score 43 is an outlier and will distort the mean (84, in this case) would give a better sense of the overall scores.

A means of selecting respondents that generates a sample in which some groups are over-represented compared to their share of the target population. This method allows for analysis of groups that would otherwise make up such a small percent of the sample that analysis would be difficult. For instance, oversampling Asian Americans in a survey of US citizens may allow for a more accurate analysis of this group. Oversamples are generally weighted down to their share of the population when results are aggregated to report overall results.

The theoretical population from which the sample was drawn. For example, adults living in the contiguous U.S.; Some studies are based on sample sub-sets (such as national samples of women or African Americans).

A characteristic of the target population described by a statistic. For example, if your target population is runners in the New York City Marathon, the average finishing time would be a population parameter. You calculate every runners' finishing time to get the parameter. (Not to be confused with sample statistic)

In iPOLL, this is the total unweighted count of all completed interviews, also referred to as the sample size.

A technique of adjusting weights on respondents in a survey so the adjusted weights add up to the known population sizes within each group, making the sample more closely resemble the target population. Poststratification is used when the grouping of like units is not possible during sampling. It is used in order to reduce bias and improve the precision of estimates. For instance, if respondents are selected for a survey and their gender is not known in advance, the gender distribution in the sample could be different from the gender distribution in the target population. Poststratification would be used in this case to adjust the weights of each gender to match the target population.

The lead researcher on a grant-funded study, often referred to as the PI.

A type of sampling which ensures that each member of the sampling frame has an equal, known chance of being selected. This kind of sampling allows researchers to make statistical inferences about the population at large. (see Non-probability Sampling)

A technique used to adjust weights on different observations in an analysis based on their likelihood of receiving the treatment the analyst is interested in, given all other characteristics. Propensity score weighting is used in order to reduce selection bias and is commonly used by online polls to weight based on the likelihood of a respondent to have oneline access.

A survey that is primarily intended to manipulate or influence respondents' opinion rather than to generate data for analysis. Push polls are especially used in political campaigning in order to influence potential voters under the guise of conducting a legitimate survey. Roper Center's acquisition policy excludes push polls.

The actual wording of the question. If additional information, such as text from a preceding question, is required for the question to be independently understandable, the added text will appear in parentheses. Similarly, the stem of multipart questions will be repeated and displayed in paratheses. For example: "(For each one, please tell me if you think it is a very serious problem, somewhat serious, not too serious, or not a problem at all.)...The large amount of American debt that is held by China."  In iPOLL the question text is preceded by a number such as R18, Q08, or R02. This unique designation is assigned by the Roper Center and does not necessarily reflect the order in which the question appeared in the original study. Whenever possible the original survey instrument is used as the source document by Center staff. In many cases, though, the order of questions on the survey may have been altered in some way for publication in a final report or news release. Researchers requiring information on the original question order should contact the Roper Center.

The actual wording of the question used during the survey interview. 

A means of sampling or selecting people to participate in surveys based on specific characteristics (such as age or gender). The objective is often to generate a sample that closely reflects the target population with regard to these characteristics, in order to reduce bias. For instance, if the target population consists of 50% men and 50% women, one might use quota sampling to recruit an equal number of men and women. In contrast to stratified sampling, quota sampling is a type of non-probability sampling.

A type of poststratification procedure that adjusts the sample weights in a survey in order to make the sample match the target population more closely with regard a number of different groups or post-strata (such as gender, race, age, etc). Raking adjusts the sample weights through repeated calculation of weights so they add up to the known population totals for the post-stratified classifications when only the marginal population totals are known (e.g. if the gender and age distribution of the population is known, but not the gender distribution for each age group).

A technique used to obtain a representative sample by using a device that randomly generates telephone numbers in order to contact eligible participants.

A ratio variable has all the properties of an interval variable. In addition, it has a zero point. For example, income.

Survey respondents who either have to be contacted multiple times in order to be reached, or are contacted again after the initial survey has been conducted (e.g. to validate completed interviews or to measure behavioral changes over time).

An instance in which a survey respondent selected to participate in a survey declines to do so or declines to answer one or more questions in the survey. This is a type of nonresponse that can bias survey results.

A means of sampling or selecting people to participate in election polls using a database of registered voters for a given geographical area. With RBS, the sampling frame from which the sample is drawn consists of the registered voters for the area.

Interviews conducted with respondents who participated in a previous survey. Reinterviews are used in order to track changes in respondents' opinions over time or before and after an event, such as a presidential debate.

The quality of measurement that suggest that the same data would have been collected each time in repeated observations of the same phenomenon.

When applicable, the name of the organization that commissioned the survey.

The process of choosing the final respondent for a survey; for example, choosing the respondents for a particular survey from an online panel or choosing members of a household to participate in a survey once the household has already been selected (e.g. through random digit dialing).

Proportion of contacted respondents who completed the survey. The American Association for Public Opinion Research (AAPOR) provides definitions for six measures of response rates (AAPOR response rate definitions).

The response categories and percentages of the sample answering each way. Generally, the percentages shown are weighted if the data were weighted better to reflect the population. Any special question-related information clarifying such things as multiple responses, partial responses, and the like will appear after the responses. These notes relate only to specific questions as opposed to the entire study and are referred to as question-level notes.

See raking.

A means of sampling or selecting people to participate in surveys in which potential survey respondents are recruited through online ads or pop-ups on online platforms. It is a type of non-probability sampling in which the respondent's identity is unverifiable and the respondent cannot be recontacted. A respondent would typically click on an ad or offer, answer a number of pre-screening questions, and then be routed to a survey.

Online survey routs screen respondents and directs them to open surveys for which they are qualified.

A description of the population from which the survey respondents were drawn.

One type of inaccuracy caused by making inferences about the target population based on the sample. The sampling error is an estimate of how a sample statistic is expected to differ from the population parameter.

This is the list of eligible participants included in the target population. The sample is chosen from the sampling frame.

This is the total unweighted count of all completed interviews.

A statistic which describes the sample. (e.g. If you want to do a survey of New York City Marathon runners, including their finishing times, the average finishing time of the those surveyed would be an example of a sample statistic. Not to be confused with population parameter, which would calculate the average finishing time of all the runners, not just a sample of them.)

A method of selecting elements (or units) from the target population in a way that is representative. Types of sampling include: Simple random sampling, stratified sampling, systematic sampling, and multi-stage cluster sampling.

The method by which participants in a poll were selected.

This term refers to materials and information that has previously been documented. For example, a poll, a press release, a business report.

The most common sampling method where each element in the population has an equal chance of being selected.

The document from which information was gathered. In iPOLL, the source document usually refers to the topline document released by a polling organization which was used as the source for questions and topline results. 

Respondents answering at a rate too fast to allow for adequate comprehension of questions, particularly for paper or online questionnaires.

A type of survey research design in which a sample is randomly split into different groups and assigned different treatments (e.g. questions or prompts) in order to determine the effect of the treatment on survey responses. A sample may also be split into groups and asked different questions in order to maximize the number of questions that can be asked in the survey.

A statistic that shows the dispersion of scores in a distribution of scores. It is a measure of the average amount the scores in a distribution deviate from the mean. The more widely spread out the scores are, the larger the standard deviation will be.

A statistic indicating how much the mean score of a single sample is likely to differ from the mean score of the population. It answers the question, "How good an estimate of the population mean is the sample mean?" (Not to be confused with sampling error)

A number that describes some characteristic of a variable. (e.g. the mean, the standard deviation)

A respondent providing identical answers across a range of questions (on a printed survey, literally marking off responses in a "straight line" through the instrument).

A method of sampling where groups that might not otherwise be equally represented are first divided proportionately into categories (“strata”); then, a sample is randomly selected from each of these categories. (e.g. If you wanted to do a study on hospitals, you’d separate them by size—small, medium-sized, and large hospitals. From there, you would draw samples from each category so that they’d all be equally represented.

This note field on questions in the iPOLL database pertains to the entire release, report, or study from which the question was taken.

The topic classification(s) that best describe the question. The scheme for this categorization was developed by the Roper Center and contains over 100 subject categories.

A subset of the population under study.  In cases where responses are not based on the entire sample, question results in iPOLL will show the Subpopulation field with a description of the portion of the sample whose responses are being reported appears here (e.g. women, or those who favor a given policy).

The organization that conducted the fieldwork for a survey.

A method of sampling where units are selected from the sampling frame by every “nth” unit. (e.g. You have a directory of 100,000 names and you want a sample of 1,000 names. Divide 100,000 by 1,000 to get 100. You will select every 100th name from the directory. Randomly select a number between 1 and 100, say 42, and select every 42nd name in groups of 100 (42, 142, 242, 342, 442.) to complete your sample.

A technique of adjusting weights on respondents in a survey based on the estimated probability that the respondent would be found at home at the time the interview was completed. This type of weighting is used in order to reduce bias that would result from under-representing respondents who are difficult to reach at home. This method was used by Gallup to weight face to face, probability-based surveys from the 1960s to 1980s and is still used for weighting in-person interviews in some areas.

The subject classification(s) that best describe the question. The scheme for this categorization was developed by the Roper Center and contains over 100 subject categories.

The topline is the result of how the aggregated sample answered a specific question.

A series of surveys repeated over time in order to measure changes in survey responses in a target population. Tracking polls are often used over the course of electoral campaigns to measure changes in support for political candidates.

This term typically refers to the long-term patterns over time relating to topics of interest in public opinion that are measured by the repetition of the same question with unchanging wording over many years. An example of a survey that includes many important trends is the GSS, one of the nation's longest running surveys of social, cultural and political indicators.

Using more than one method to find meaning in a problem. i.e. If you want to interpret the President's Approval Rating, you could look at poll results, results of focus groups, and news stories of current events.

The analysis of a single variable, for purposes of description (e.g., averages, or the proportion of cases falling into a given category among the entire sample).

All entities that qualify for inclusion in the study or survey, from which the sample of respondents is drawn. The target population could consist of all adult American citizens, for instance, or all Fortune 500 companies.

A common theoretical population for US “national” polls. Typically it means the age 18+, non-institutionalized (e.g. no prisons, nursing homes, or military bases) population in the 48 contiguous states, since Alaska and Hawaii are often omitted for practical reasons.

In survey research, a variable is an example of what is being measured. (i.e. income, age; presidential approval; support for a policy, etc.) There are different kinds of variables, including: categorical, continuous, interval, ratio, independent, dependent.

Also known as sample balancing, weighting is a technique used to reflect differences in the number of population units that each case in a dataset represents. Typically, for surveys designed to be representative of the population of the U.S., units are adjusted to reflect the U.S. Census on several demographic measures, including age, education, and sex. While polling organizations may have different methods for their weighting procedures, weighting generally involves the multiplication of survey observations by one or more factors in order to increase or decrease the emphasis that will be given to the observations when analyzing the data. See also propensity score weighting, raking weighting, times-at-home weighting.Also known as sample balancing, weighting is a technique used to reflect differences in the number of population units that each case in a dataset represents. Typically, for surveys designed to be representative of the population of the U.S., units are adjusted to reflect the U.S. Census. While polling organizations may have different methods for their weighting procedures, weighting generally involves the multiplication of survey observations by one or more factors in order to increase or decrease the emphasis that will be given to the observations when analyzing the data.

Data source for benchmarks used to weight the sample.

The process of choosing members of a household to participate in a survey once the household has already been selected (e.g. through random digit dialing). See also Respondent selection. Examples of methods of within household selection include most recent birthday and youngest man/oldest woman designs.

A systematic, non-random technique for selecting members of a given household for a survey. The member of the household who should be selected, e.g. the youngest man, the youngest woman, the oldest man or the oldest woman, can be randomly assigned across the sample, or interviewers can always start with the youngest man, then move to the oldest woman.