There are three main types of survey research: exploratory research, descriptive research, and causal research. Exploratory research helps focus survey design and limits bias through methods like focus groups, secondary research, expert surveys, and open-ended questions. Descriptive research defines respondents and draws conclusions by gathering quantifiable information for statistical analysis of customer satisfaction, employee satisfaction, and other similar studies. Causal research identifies relationships and makes business decisions through experimentation by understanding causal and effect variables and their relationship to predict effects, such as increasing customer retention or effective advertising.