Which method can be used to reduce demand characteristics in experiments?

Implementing double-blind procedures is an effective way to reduce demand characteristics in experiments. Demand characteristics occur when participants alter their behavior based on their perceptions of what the study is about or what is expected of them. In a double-blind study, both the participants and the experimenters do not know which participants are in the control or experimental groups. This setup minimizes biases from both sides; participants are less likely to change their behavior based on perceived expectations, and experimenters are less likely to inadvertently communicate cues that could influence participants' responses. By removing this potential source of bias, the validity of the findings can be enhanced, leading to more reliable conclusions.

In contrast, conducting an open-ended survey may not effectively address demand characteristics since participants still have freedom in how they respond and might interpret the questions based on their own assumptions about the study. Increasing the sample size can improve the generalizability of the results but does not directly address how participants might change their behavior in response to perceived expectations. Providing participants with detailed background information could lead to them anticipating the study’s aims, which may increase the likelihood of demand characteristics influencing their behavior instead of reducing it.