Statistical survey

Statistical surveys are used to collect quantitative information about items in a population. Surveys of human populations and institutions are common in political polling and government, health, social science and marketing research. A survey may focus on opinions or factual information depending on its purpose, and many surveys involve administering questions to individuals. When the questions are administered by a researcher, the survey is called a structured interview or a researcher-administered survey. When the questions are administered by the respondent, the survey is referred to as a questionnaire or a self-administered survey.

Structure and standardization
The questions are usually structured and standardized. The structure is intended to reduce bias (see questionnaire construction). For example, questions should be ordered in such a way that a question does not influence the response to subsequent questions. Surveys are standardized to ensure reliability, generalizability, and validity (see quantitative marketing research). Every respondent should be presented with the same questions and in the same order as other respondents.

In organizational development (OD), carefully constructed survey instruments are often used as the basis for data gathering, organizational diagnosis, and subsequent action planning. Some OD practitioners (e.g. Fred Nickols) even consider survey guided development as the sine qua non of OD.

Serial surveys
Serial surveys are those which repeat the same questions at different points in time, producing time-series data. They typically fall into two types:
 * Cross-sectional surveys which draw a new sample each time. In a sense any one-off survey will also be cross-sectional.
 * Longitudinal surveys where the sample from the initial survey is recontacted at a later date to be asked the same questions.

Advantages of surveys
The advantages of survey techniques include:
 * It is an efficient way of collecting information from a large number of respondents. Very large samples are possible. Statistical techniques can be used to determine validity, reliability, and statistical significance.
 * Surveys are flexible in the sense that a wide range of information can be collected. They can be used to study attitudes, values, beliefs, and past behaviours.
 * Because they are standardized, they are relatively free from several types of errors.
 * They are relatively easy to administer.
 * There is an economy in data collection due to the focus provided by standardized questions. Only questions of interest to the researcher are asked, recorded, codified, and analyzed. Time and money is not spent on tangential questions.

Disadvantages of surveys
Disadvantages of survey techniques include:
 * They depend on subjects’ motivation, honesty, memory, and ability to respond. Subjects may not be aware of their reasons for any given action. They may have forgotten their reasons. They may not be motivated to give accurate answers, in fact, they may be motivated to give answers that present themselves in a favorable light.
 * Structured surveys, particularly those with closed ended questions, may have low validity when researching affective variables.
 * Although the chosen survey individuals are often a random sample, errors due to nonresponse may exist. That is, people who choose to respond on the survey may be different from those who do not respond, thus biasing the estimates.
 * Survey question answer-choices could lead to vague data sets because at times they are relative only to a personal abstract notion concerning "strength of choice". For instance the choice "moderately agree" may mean different things to different subjects, and to anyone interpreting the data for correlation.  Even yes or no answers are problematic because subjects may for instance put "no" if the choice "only once" is not available.

Advantages of self-administered questionnaires
Advantages of self-administered questionnaires include:
 * They are less expensive than interviews.
 * They do not require a large staff of skilled interviewers.
 * They can be administered in large numbers all at one place and time.
 * Anonymity and privacy encourage more candid and honest responses.
 * Lack of interviewer bias.
 * Speed of administration and analysis.
 * Suitable for computer based research methods.
 * Less pressure on respondents

Disadvantages of self-administered surveys

 * Respondents are more likely to stop participating mid-way through the survey (drop-offs)
 * Respondents cannot ask for clarification
 * Low response rate in some modes
 * No interviewer intervention available for probing or explanation
 * Often respondents returning survey represent extremes of the population - skewed responses
 * Respondents can read the whole questionnaire before answering any questions

Advantages of researcher administered interviews
Advantages of researcher administered interviews include:
 * Fewer misunderstood questions and inappropriate responses.
 * Fewer incomplete responses.
 * Higher response rates.
 * Greater control over the environment that the survey is administered in.
 * Additional information can be collected from respondent

Survey methods
There are several ways of administering a survey, including:


 * Telephone
 * response rate of approximately 40%-80%
 * fairly cost efficient, depending on local call charge structure
 * good for large national (or international) sampling frames
 * cannot be used for non-audio information (graphics, demonstrations, taste/smell samples)
 * three types:
 * traditional telephone interviews
 * computer assisted telephone dialing
 * computer assisted telephone interviewing
 * Mail
 * response rate 5% - 30%
 * the questionnaire may be handed to the respondents or mailed to them, but in all cases they are returned to the researcher via mail.
 * cost is very low, since bulk postage is cheap in most countries
 * long time delays, often several months, before the surveys are returned and statistical analysis can begin
 * not suitable for very complex issues
 * no interviewer bias introduced
 * large amount of information can be obtained: some mail surveys are as long as 50 pages
 * response rates can be improved by using mail panels
 * members of the panel have agreed to participate
 * panels can be used in longitudinal designs where the same respondents are surveyed several times
 * Online surveys
 * can use web or e-mail
 * web is preferred over e-mail because interactive HTML forms can be used
 * response rates sometimes 90% before 2000, but have been dropping fast since then (now 2% - 30%)
 * often inexpensive to administer
 * very fast results
 * easy to modify
 * response rates can be improved by using Online panels - members of the panel have agreed to participate
 * if not password-protected, easy to manipulate by completing multiple times to skew results
 * data creation, manipulation and reporting can be automated
 * data sets created in real time


 * Personal in-home survey
 * respondents are interviewed in person, in their homes (or at the front door)
 * very high cost
 * response rate 40% - 50%
 * suitable when graphic representations, smells, or demonstrations are involved
 * suitable for long surveys
 * suitable for locations where telephone or mail are not developed
 * Personal mall intercept survey
 * shoppers at malls are intercepted - they are either interviewed on the spot, taken to a room and interviewed, or taken to a room and given a self-administered questionnaire
 * response rate about 50%
 * socially acceptable - people feel that a mall is a more appropriate place to do research than their home
 * potential for interviewer bias
 * fast
 * easy to manipulate by completing multiple times to skew results

Methods used to increase response rates

 * brevity - single page if possible
 * financial incentives
 * paid in advance
 * paid at completion
 * non-monetary incentives
 * commodity giveaways (pens, notepads)
 * entry into a lottery, draw or contest
 * discount coupons
 * promise of contribution to charity
 * preliminary notification
 * foot-in-the-door techniques - start with a small inconsequential request
 * personalization of the request - address specific individuals
 * follow-up requests - multiple requests
 * claimed affiliation with universities, research institutions, or charities
 * emotional appeals
 * bids for sympathy
 * convince respondent that they can make a difference
 * guarantee anonymity

Doctoral and Masters Degrees

 * Joint Program in Survey Methodology (JPSM) - University of Maryland-College Park and University of Michigan-Ann Arbor
 * Survey Research and Methodology - University of Nebraska-Lincoln
 * Program in Survey Methodology - University of Michigan-Ann Arbor
 * Social Statistics - University of Southampton

Masters Degrees only

 * Graduate Program in Survey Research - University of Connecticut
 * Diploma in Official Statistics - Hebrew University, Israel
 * Methodology and Statistics for the Social and Behavioral Sciences - Utrecht University, the Netherlands
 * Postgraduate Certificate/Diploma/M.Sc. in Social Research Skills with Specialisms - University of Ulster, Northern Ireland

Lists of related topics

 * List of accounting topics
 * List of economics topics
 * List of finance topics
 * List of management topics
 * List of marketing topics