Which of the following are examples of primary data types commonly collected during fieldwork?

• A. Measurements only
• B. Observations only
• C. Questionnaires only
• D. Measurements, observations and questionnaires

Answer: (D)

Primary data collected during fieldwork comes from data you gather yourself for a specific study. In practice you often obtain measurements (quantitative numbers like length, temperature, depth), you make observations (descriptions of what you see or what happens, which can be qualitative or quantitative), and you use questionnaires to capture respondents’ answers (surveys that yield numerical or descriptive data). Together these cover the main ways researchers collect firsthand information on site, so including all three gives the most complete picture of the data you typically gather in fieldwork. Focusing on just one type misses other common primary data sources you might combine in a study.