Describe the major contact methods used to collect information from respondents in market research

What will be an ideal response?

Information can be collected by mail, telephone, personal interview, or online.
Mail questionnaires can be used to collect large amounts of information at a low cost per respondent. Respondents may give more honest answers to more questions by mail than to an unknown interviewer in person or on the phone. Also, no interviewer is involved to bias respondents' answers.
Telephone interviewing is one of the best methods for gathering information quickly, and it provides greater flexibility than mail questionnaires. Interviewers can explain difficult questions and, depending on the answers they receive, skip some questions or probe on others. Response rates tend to be higher than with mail questionnaires, and interviewers can ask to speak to respondents with the desired characteristics or even by name.
Personal interviewing takes two forms: individual interviewing and group interviewing. Individual interviewing involves talking with people in their homes or offices, on the street, or in shopping malls. Such interviewing is flexible. Group interviewing consists of inviting 6 to 10 people to meet with a trained moderator to talk about a product, service, or organization. Participants normally are paid a small sum for attending. A moderator encourages free and easy discussion, hoping that group interactions will bring out actual feelings and thoughts.
Online research can take many forms. A company can use the Internet or mobile technology as a survey medium: It can include a questionnaire on its Web or social media sites or use e-mail or mobile devices to invite people to answer questions. It can create online panels that provide regular feedback or conduct live discussions or online focus groups. Researchers can also conduct online experiments.