controlled experiment

Controlled experiments follow a strict protocol, a predefined number of trials, often in a laboratory setting. In HCI, controlled experiments may influence results. For example, experts may behave more like novices in the artificial environment of a lab experiment, being more careful about their actions and monitoring the results. Typically, controlled experiments have to sacrifice ecological validity, being less like the equivalent real-world activity. Contrast with ethnographic methods and in-the-wild studies.