John Henry Effect
The John Henry effect is a distortion of the results or source of error in experiments in the social sciences . This describes a reactive behavior of the control group in a comparison group study in order to minimize or resolve the (performance) difference to the experimental group. To do this, however, they must be aware that they belong to the control group and be able to compare themselves with the experimental group with regard to the measured property ( dependent variable ).
For example, one school class could make more effort to compensate for the disadvantage compared to another school class to which an additional teacher was assigned. As a countermeasure, the assignment can be blinded or a guideline recorded before the start of the experiment in order to determine the effect at all.
The term was first used by Gary Saretsky (1972) to describe the behavior of the American railroad worker John Henry . After he learned that his work performance should be compared to that of a steam engine, he overexerted himself to such an extent that he died of the consequences.
See also
literature
- Markus Pospeschill: Empirical Methods in Psychology . tape 4010 . UTB, Munich 2013, ISBN 978-3-8252-4010-3 .
Individual evidence
- ^ Saretsky, G. (1972). "The OEO PC experiment and the. John Henry Effect," Phi Delta Kappan 53: 579-581