Note: * Precertification of denosumab (Prolia and Xgeva) is required of all Aetna participating providers and members in applicable plan designs. For precertification of denosumab (Prolia and Xgeva), call (866) 503-0857, or fax (866) 267-3277.
Observer Expectancy Effect. The observer expectancy effect, also called the experimenter expectancy effect, is a phenomenon that can occur when a researcherâs beliefs or expectations cause him or her to unconsciously influence the participants of an experiment. In order to conserve the internal validity of an experiment, researchers can use a double-blind experimental design.
Experimenter's bias is the phenomenon in experimental science by which the outcome of an experiment tends to be biased towards a result expected by the human experimenter.The inability of a human being to remain completely objective is the ultimate source of this bias.n principle, if a measurement has a resolution of, then if the experimenter averages independent measurements the average will have a resolution of (this is the central limit theorem of statistics). This is an important experimental technique used to reduce the impact of randomness on an experiment's outcome.