Conducting Interviews allow researchers to learn detailed information from individuals. It is useful when you want to learn more about indivduals who experience something first hand first or talk to someone knowledgeable about a topic. There are several different types of interviews including: face to face, phone, email, and chat.
The moderator's survival guide: Handling common, tricky, and sticky situations in user research by 
Research interviewing: The range of techniques by Survey research involves the use of questionnaires and/or statistical surveys to gather data about people and their thoughts and behaviors.
Assessing the Quality of Survey Data by 
Design, evaluation, and analysis of questionnaires for survey research by 
Social Media, Sociality, and Survey Research by A focus group is a form of qualitative research in which a group of people are asked about their perceptions, opinions, beliefs and attitudes towards a product, service, concept, advertisement, idea, or packaging. Questions are asked in an interactive group setting where participants are free to talk with other group members.
Focus Groups: A Practical Guide for Applied Research by 
