Observer Effect:The observer effect is a scientific principle which states that the mere observation of a phenomenon inevitably changes that phenomenon, rendering the measurement inaccurate.
Reactivity: Reactivity refers to the tendency of individuals to change their behavior or performance in response to being observed or measured, which can impact the validity of research findings.
Experimental Bias: Experimental bias occurs when the results of a study are influenced by factors other than the independent variable, such as the expectations or behaviors of the researchers or participants.