Final answer:
Expectancy effects are influenced by people's expectations or beliefs and can bias experiment results. Experimenters control for these effects through blinding and placebo control.
Step-by-step explanation:
Expectancy effects refer to the influence of people's expectations or beliefs on their experience in a given situation. They can impact the results of an experiment by biasing the participant's response to the independent variable. To control for expectancy effects, experimenters can use two main methods:
- Blinding: This involves keeping the participants or experimenters unaware of which group they are assigned to. This prevents their expectations from influencing the results.
- Placebo Control: Providing a placebo treatment to the control group can help control for expectancy effects. The placebo treatment looks like the active treatment but has no real effect. This helps determine if any observed effects are due to the treatment or simply the participant's expectations.