EffectBelief updating · Confirmation Bias · Entry 24
Observer-Expectancy Effect – when wanting a result makes it appear
Does a researcher believe in a certain outcome and unconsciously shape the data to fit? That’s Observer-Expectancy Effect – when an experimenter unintentionally influences results by modifying the experiment or interpreting data in a biased way.
Where it can show up
- Science – a researcher expecting a drug to work notices improvements even where none exist.
- Education – a teacher expects better performance from ‘gifted’ students and grades them more leniently.
- Sports – a referee unconsciously calls more fouls against a team they view negatively.
A practical countermeasure
- Use blind methods – don’t know the expected results beforehand to avoid influencing them.
- Record data objectively – avoid interpreting results to fit expectations.
- Ask yourself: what if I expected the opposite? – this helps view the data without bias.
