Validity is the representation of measurement accuracy in survey methods. In order to design a valid question, the researched issue must be determined. A valid question accurately reflects the topic while encompassing key variables. Essentially, it is important to phrase the questions so that the potential answers provide the researcher with the data set that they intend to measure. Meanwhile, reliability focuses on the consistency and integrity of the measurements. Reliability seeks to eliminate random errors that may arise by responders guessing the answer due to a lack of knowledge or understanding. The same result of repetitive attempts shows reliability. Reliability and validity are inherently independent of each other, but both are needed for a successful survey.
The two general surveying techniques are considered questionnaires and interviews. The researcher selects one situationally based on types of populations, sampling, and question content. The questionnaire is a written form of data collection with closed and objective types of questions with the sole purpose of compiling factual evidence. Meanwhile, interviews are an ongoing oral conversation between the researcher and the respondent. Interviews are free-flowing and subjective, giving more flexibility to approach. The collected information can be factual but also presents an analytical perspective.
Both survey methods have strengths and limitations. Questionnaires are cheap and efficient but lack human guidance in clarity and analysis. Also, questionnaires are anonymous and have high rates of non-responders. Interviews give the researcher the direct ability to control the discussion while presenting information about identity. Obviously, with interviews, the rate of response is high, but they are also costly and time-consuming due to staff involvement. Also, interviews, due to their open-ended nature, can present invalid or skewed results because the researcher can commit human error or bias.