Editing Observer-expectancy effect (section)

{{Short description|Cognitive bias of experimental subject}}
{{Other uses|Observer effect (disambiguation)|Expectancy effect (disambiguation){{!}}Expectancy effect}}
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The '''observer-expectancy effect'''{{efn|Also called the '''experimenter-expectancy effect''', '''expectancy bias''', '''observer effect''', or '''experimenter effect'''.}} is a form of [[Reactivity (psychology)|reactivity]] in which a [[researcher]]'s [[cognitive bias]] causes them to subconsciously influence the participants of an experiment. [[Confirmation bias]] can lead to the [[experiment]]er interpreting results incorrectly because of the tendency to look for information that conforms to their hypothesis, and overlook information that argues against it.<ref>Goldstein, Bruce. "Cognitive Psychology". Wadsworth, Cengage Learning, 2011, p. 374</ref> It is a significant threat to a study's [[internal validity]], and is therefore typically [[experimental control|controlled]] using a [[double-blind experiment|double-blind experimental design]].

It may include conscious or unconscious influences on subject behavior including creation of [[demand characteristics]] that influence subjects, and altered or selective recording of experimental results themselves.<ref name="KantowitzIII2009">{{cite book|author1=Barry H. Kantowitz|author2=Henry L. Roediger, III|author3=David G. Elmes|title=Experimental Psychology|url=https://books.google.com/books?id=2-5VL8PHLsIC&pg=PA371|access-date=7 September 2013|year=2009|publisher=Cengage Learning|isbn=978-0-495-59533-5|page=371}}</ref>