What factors could lead to participant attrition in an experimental study?

Participant attrition, or dropout, can significantly impact the validity and reliability of an experimental study's results. Each factor mentioned contributes to the reasons why participants may choose to leave a study.

A lack of interest can occur if participants do not find the study engaging or relevant to their interests, leading them to withdraw. If participants are not invested in the study's目的, they may feel less committed to continuing their participation.

Adverse effects refer to any negative physical or psychological experiences that participants may encounter as a result of the study's procedures or treatments. If participants experience discomfort or negative side effects, they may decide that the risks outweigh the benefits, prompting them to drop out.

Inability to complete the study protocol can arise from various logistical challenges, including time constraints, personal obligations, or health issues that make it difficult for participants to adhere to the study requirements. If participants struggle to keep up with the demands of the study, they might choose to exit rather than face these challenges.

Given that all of these factors can substantially influence participants' decisions about whether to continue or discontinue their involvement in a study, the correct answer encompasses all the potential reasons for participant attrition.