The Hawthorne effect refers to a phenomenon which is thought to occur when people observed during a research study temporarily change their behavior or performance (this can also be referred to as
demand characteristics). Others have broadened this definition to mean that people’s behavior and performance change following any new or increased attention. The Hawthorne studies have had a dramatic effect on management in organizations and how people react to different situations.
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The concept that every change results (initially, at least) in increased productivity.