Interviews

Interviews are a type of qualitative data in which the researcher asks questions to elicit facts or statements from the interviewee. Interviews used for research can take several forms:

• Informal Interview: A more conversational type of interview, no questions are asked and the interviewee is allowed to talk freely.
• General interview guide approach: Ensures that the same general areas of information are collected from each interviewee. Provides more focus than the conversational approach, but still allows a degree of freedom and adaptability in getting the information from the interviewee.
• Standardized, open-ended interview: The same open-ended questions are asked to all interviewees. This approach facilitates faster interviews that can be more easily analyzed and compared.
• Closed, fixed-response interview (Structured): All interviewees are asked the same questions and asked to choose answers from among the same set of alternatives. 

Surveys

The survey method of data collection is a type of descriptive research, and is likely the most common of the major methods. Surveys have limited use for studying actual social behavior but are an excellent way to gain an understanding of an individual's attitude toward a matter.

Similar to an interview, a survey may use close-ended questions, open-ended questions, or a combination of the two. "Closed-ended questions" are questions that limit the person taking the survey to choose from a set of responses. Multiple choice, check all that apply, and ratings scale questions are all examples of closed-ended questions. "Open-ended questions" are simply questions that allow people to write in their own response.

Surveys are a highly versatile tool in psychology. Although a researcher may choose to only administer a survey to sample of individuals as their entire study, surveys are often used in experimental research as well. For example, a researcher may assign one group of individuals to an experimental condition in which they are asked to focus on all the negative aspects of their week to induce a negative mood, while he assigns another group of people to a control group in which they read a book chapter. After the mood induction, he has both groups fill out a survey about their current emotions. In this example, the mood induction condition is the independent (manipulated) variable, while participants' responses on the emotion survey is the dependent (measured) variable.

Advantages of Surveys

The benefits of this method include its low cost and its large sample size. Surveys are an efficient way of collecting information from a large sample and are easy to administer compared with an experiment. Surveys are also an excellent way to measure a wide variety of unobservable data, such as stated preferences, traits, beliefs, behaviors, and factual information. It is also relatively simple to use statistical techniques to determine validity, reliability, and statistical significance.

Surveys are flexible in the sense that a wide range of information can be collected. Since surveys are a standardized measure, they are relatively free from several types of errors. Only questions of interest to the researcher are asked, codified, and analyzed. Survey research is also a very affordable option for gathering a large amount of data.

Disadvantages of Surveys

The major issue with this method is its accuracy: since surveys depend on subjects' motivation, honesty, memory, and ability to respond, they are very susceptible to bias. There can be discrepancies between respondents' stated opinions and their actual opinions that lead to fundamental inaccuracies in the data. If a participant expects that one answer is more socially acceptable than another, he may be more motivated to report the more acceptable answer than an honest one. 

When designing a survey, a researcher must be wary of the wording, format, and sequencing of the questions, all of which can influence how a participant will respond. In particular, a researcher should be concerned with the reliability of their survey. "Reliability" concerns the degree to which the survey questions are likely to yield consistent results each time. A survey is said to have high reliability if it produces similar results each time. For example, a reliable measure of emotion is one that measures emotion the same way each time it is used. However, for a survey to be useful, it needs to be not only reliable, but valid. If a measure is has high "validity", this means that it is in fact measuring the concept it was designed to measure (in this case, emotion). It is important to note that a survey can be reliable, but not valid (and vise versa). For example, just because our emotion survey is reliable, and provides us with consistent results each time we administer it, does not necessarily mean it is measuring the aspects of emotion we want it to. In this case, our emotion survey is reliable, but not necessarily valid.

Structured surveys, particularly those with closed-ended questions, may have low validity when researching affective variables. Survey samples tend to be self-selected since the the respondents must choose to complete the survey. Surveys are not appropriate for studying complex social phenomena since they do not give a full sense of these processes. 

Key Elements of a Successful Survey or Interview

While survey research is one of the most common types of psychological study, it can be difficult to create a survey that is free of bias and that reliably measures the factors it aims to capture. A researcher must have a strong understanding of the basics before they can create a valid survey from scratch. Surveys must be carefully worded and include appropriate response formats. The way a question is written can confuse a participant or bias their response, and poorly framed or ambiguous questions will likely result in meaningless responses with very little value. Questions should be clear, address only one topic at a time, and avoid leading the respondent to a specific answer (in other words, a question should not suggest the correct response in how it is worded). When designing a survey, it is important to understand your audience and use words they will understand and make sure your survey is not too long for them to easily complete.

Survey research books

While survey research is one of the most common types of psychological study, it can be difficult to create a survey that is free of bias and that reliably measures the factors it aims to capture. A researcher must have a strong understanding of the basics before they can create a valid survey from scratch.

Types of Data Gathered in Surveys and Interviews

Surveys may measure either qualitative or quantitative data. Qualitative data are the result of categorizing or describing attributes of a population such as hair color, blood type, or ethnic group. Qualitative data are usually described by words or letters. This type of data does not lend itself to mathematical analysis, but bar graphs and pie charts tend to demonstrate this type of data well.

Quantitative data are always numbers. Quantitative data are the result of counting or measuring attributes of a population, such as money, pulse rate, weight, or populations. This type of data may be either discrete (meaning they take on only certain numerical values, such as the number of phone calls you receive per day or the number of jeans you own—you might have 2 or 3 pairs of jeans, but you cannot have 2.5 pairs) or continuous (data that are the result of measurements such as weight, height, or amount of blood donated). Discrete data use whole numbers, while continuous data utilize decimals and fractions.