Title

Context:

Census: data collection about everyone or everything in a population
- Advantages: high accuracy
- Disadvantages: expensive, time-consuming, out of date
Sample survey: data collection from a part of the population
- Advantages: less expensive, faster
- Disadvantages: less accurate, depends on sample size and methods
Primary and Secondary data
- Primary: data collected directly for the purpose of the survey
- Secondary: data collected for some other purpose, but can be used for the survey
Methods of Obtaining Sample Data
- Observation: gathering data by watching behavior, events, or characteristics in their natural setting
  - Advantages: understand ongoing process or situation, gather data on individual behaviors or interactions, know about physical setting
  - Disadvantages: data collection from individuals may not be realistic
- Experimentation: testing competing models or hypotheses, or testing existing theories or new hypotheses
- Qualitative techniques: investigating the why and how of decision making, using smaller but focused samples
- Questionnaires: series of questions for gathering information from respondents
  - Advantages: quick, cheap, standardized answers
  - Disadvantages: may frustrate respondents, may lead to biased results
  - Methods: phone or personal interviews, postal surveys, self-completion