A single survey is made of at least a sample (or full population in the case of a census), a method of data collection (e.g., a
questionnaire) and individual questions or items that become data that can be analyzed statistically. A single survey may focus on different types of topics such as preferences (e.g., for a presidential candidate), opinions (e.g., should abortion be legal?), behavior (smoking and alcohol use), or factual information (e.g., income), depending on its purpose. Since survey research is almost always based on a sample of the population, the success of the research is dependent on the representativeness of the sample with respect to a target population of interest to the researcher. That target population can range from the general population of a given country to specific groups of people within that country, to a membership list of a professional organization, or list of students enrolled in a school system (see also
sampling (statistics) and
survey sampling). The choice between administration modes is influenced by several factors, including 1) costs, 2) coverage of the target population (including group-specific preferences for certain modes), 3) flexibility of asking questions, 4) respondents' willingness to participate and 5) response accuracy. Different methods create
mode effects that change how respondents answer. The most common modes of administration are listed under the following headings.
Mobile surveys Mobile data collection or mobile surveys is an increasingly popular method of data collection. Over 50% of surveys today are opened on mobile devices. The survey, form, app or collection tool is on a mobile device such as a smart phone or a tablet. These devices offer innovative ways to gather data, and eliminate the laborious "data entry" (of paper form data into a computer), which delays data analysis and understanding. By eliminating paper, mobile data collection can also dramatically reduce costs: one World Bank study in Guatemala found a 71% decrease in cost while using mobile data collection, compared to the previous paper-based approach. Apart from the high mobile phone penetration, further advantages are quicker response times and the possibility to reach previously hard-to-reach target groups. In this way, mobile technology allows marketers, researchers and employers to create real and meaningful mobile engagement in environments different from the traditional one in front of a desktop computer. However, even when using mobile devices to answer the web surveys, most respondents still answer from home.
SMS/IM surveys SMS surveys can reach any handset, in any language and in any country. As they are not dependent on internet access and the answers can be sent when its convenient, they are a suitable mobile survey data collection channel for many situations that require fast, high volume responses. As a result, SMS surveys can deliver 80% of responses in less than 2 hours and often at much lower cost compared to face-to-face surveys, due to the elimination of travel/personnel costs. IM is similar to SMS, except that a mobile number is not required. IM functions are available in standalone software, such as Skype, or embedded on websites such as Facebook and Google. and even that the quality of a series of questions in an online opt-in panel (Netquest) was very similar to the measurement quality for the same questions asked in the
European Social Survey (ESS), which is a face-to-face survey. Some studies have compared the quality of face-to-face surveys and/or telephone surveys with that of online surveys, for single questions, but also for more complex concepts measured with more than one question (also called Composite Scores or Index). Focusing only on probability-based surveys (also for the online ones), they found overall that the face-to-face (using show-cards) and web surveys have quite similar levels of measurement quality, whereas the telephone surveys were performing worse. Other studies comparing paper-and-pencil questionnaires with web-based questionnaires showed that employees preferred online survey approaches to the paper-and-pencil format. There are also concerns about what has been called "ballot stuffing" in which employees make repeated responses to the same survey. Some employees are also concerned about privacy. Even if they do not provide their names when responding to a company survey, can they be certain that their anonymity is protected? Such fears prevent some employees from expressing an opinion.
Advantages of online surveys • Web surveys are faster, simpler, and cheaper. Online surveys are also less intrusive, and they suffer less from social desirability effects. •
Invitations to online surveys. Due to the lack of sampling frames many online survey invitations are published in the form of an URL link on web sites or in other media, which leads to sample selection bias that is out of research control and to non-probability samples. Traditional solicitation modes, such as telephone or mail invitations to web surveys, can help overcoming probability sampling issues in online surveys. However, such approaches are faced with problems of dramatically higher costs and questionable effectiveness. •
Questionnaire design. While modern web questionnaires offer a range of design features (different question types, images, multimedia), the use of such elements should be limited to the extent necessary for respondents to understand questions or to stimulate the response. It should not affect their responses, because that would mean lower validity and reliability of data. Appropriate questionnaire design can help lowering the measurement error that can arise also due to the respondents or the survey mode itself (respondent's motivation, computer literacy, abilities, privacy concerns, etc.).
Telephone Telephone surveys use interviewers to encourage the sample persons to respond, which leads to higher response rates. There are some potential for interviewer bias (e.g., some people may be more willing to discuss a sensitive issue with a female interviewer than with a male one). Depending on local call charge structure and coverage, this method can be cost efficient and may be appropriate for large national (or international)
sampling frames using traditional phones or
computer assisted telephone interviewing (CATI). Because it is audio-based, this mode cannot be used for non-audio information such as graphics, demonstrations, or taste/smell samples.
Mail Depending on local bulk mail postage, mail surveys may be relatively lower cost compared to other modes. The field method tends to be longer - often several months - before the surveys are returned and statistical analysis can begin. The questionnaire may be handed to the respondents or mailed to them, but in all cases they are returned to the researcher via mail. Because there is no interviewer presence, the mail mode is not suitable for issues that may require clarification. However, there is no interviewer bias and respondents can answer at their own convenience (allowing them to break up long surveys; also useful if they need to check records to answer a question). To correct nonresponse bias, extrapolation across waves could be done. Response rates can be improved by using mail panels (members of the panel must agree to participate) and prepaid monetary incentives, but response rates are affected by the class of mail through which the survey was sent. Panels can be used in longitudinal designs where the same respondents are surveyed several times. Visual presentation of survey questions make a difference in how respondents answer them; with four primary design elements: words (meaning), numbers (sequencing), symbols (e.g. arrow), and graphics (e.g. text boxes).
Face-to-face The face-to-face mode is suitable for locations where telephone or mail are not developed. Like the telephone mode, the interviewer presence runs the risk of interviewer bias.
Video interviewing Video interviewing is similar to face-to-face interviewing except that the interviewer and respondent are not physically in the same location, but are communicating via video conferencing such as
Zoom or
Teams.
Mixed-mode surveys Researchers can combine several above methods for the data collection. For example, researchers can invite shoppers at malls, and send willing participants questionnaires by emails. With the introduction of computers to the survey process, survey mode now includes combinations of different approaches or mixed-mode designs. Some of the most common methods are: •
Computer-assisted personal interviewing (CAPI): The computer displays the questions on screen, the interviewer reads them to the respondent, and then enters the respondent's answers. • Audio computer-assisted self-interviewing (audio CASI): The respondent operates the computer, the computer displays the question on the screen and plays recordings of the questions to the respondents, who then enters his/her answers. •
Computer-assisted telephone interviewing (CATI) •
Interactive voice response (IVR): The computer plays recordings of the questions to respondents over the telephone, who then respond by using the keypad of the telephone or speaking their answers aloud. • Web surveys: The computer administers the questions online. See
computer-assisted web interviewing (CAWI). ==Interpretation==