experimenter

An experimenter is a person who conducts experiments to test hypotheses, collect data, and validate theories. They may be researchers, technicians, or students. In scientific practice, the experimenter designs studies, selects methods, operates equipment, records observations, and analyzes results. The role can involve field or laboratory work.

Experimenters use controls, randomization, replication, and blinding to reduce bias. They must document procedures, calibrate instruments, and ensure data quality. In some fields, the experimenter's presence can influence participants, a phenomenon known as the experimenter expectancy effect or Rosenthal effect.

To address biases, researchers use single-blind or double-blind designs, standardized protocols, preregistration, and independent replication. Ethical considerations include informed consent, deception where allowed, minimization of risk, and data integrity.

Effective experimenters typically have training in statistics, research design, data analysis, and domain knowledge. They may work in academia, industry, or government laboratories.