What does reactivity refer to in the context of research?

Reactivity in research refers to the phenomenon where participants alter their behavior due to being aware that they are being observed or measured. This change can be influenced by the nature of the interaction, the environment, or the perceived expectations of the researchers. In the context of social treatment, individuals may behave differently in a controlled setting than they would naturally, typically aiming to conform to perceived social norms or the researcher’s expectations. This can lead to data that does not accurately reflect typical behavior, thus impacting the validity of the research findings.

The other options address different aspects of biases and changes in research but do not directly align with the concept of reactivity. Alterations observed over time pertain more to longitudinal studies and the natural progression of variables rather than the immediate behavioral response to observation. Bias due to instrumentation relates to errors or inconsistencies arising from the tools used to gather data, while selection bias pertains to the non-random selection of participants, which can skew results. Each of these factors can influence research outcomes, but they do so in ways distinct from the immediate behavioral changes caused by awareness of observation that define reactivity.