In an experimental study examining whether the way angry encounters end affects children's emotional reactions, the dependent variable would be the __________.

Correct Answer: D

Rationale: In an experimental study examining whether the way angry encounters end affects children's emotional reactions, the dependent variable would be the children's emotional reactions. The dependent variable is the outcome being measured or tested in an experiment. In this study, the researchers are trying to understand how the way angry encounters end influences children's emotions. Therefore, the emotional reactions of the children would be the dependent variable that is being studied and measured in relation to the way angry encounters end. Choices A, B, and C are not the dependent variable in this scenario. While they may be related factors, the main focus of the study is on how the way angry encounters end impacts children's emotional reactions, making children's emotional reactions the dependent variable.

Correct Answer: B

Rationale: One challenge associated with longitudinal research is that participants may relocate or drop out of the study over time. This can result in missing data and potential biases in the findings, impacting the study's overall validity and reliability. Furthermore, it can present difficulties for researchers in accurately monitoring and analyzing changes in individuals over an extended period. Options A, C, and D are incorrect because longitudinal research can indeed allow for inferences about cause-and-effect relationships, findings can be generalized to the real world with appropriate design and sampling, and it is suitable for studying individual developmental patterns.

Correct Answer: D

Rationale: Cross-sectional studies can be threatened by cohort effects because different age groups may have experienced different historical or social contexts, influencing the results. This disparity can lead to invalid comparisons between age groups, confounding the study's findings. Option A, practice effects, refer to changes in participants' behavior due to repeated testing, not a specific threat to cross-sectional studies. Participant dropout (Option B) is a threat related to attrition in longitudinal studies, not cross-sectional studies. Sequential timing (Option C) does not pose a threat to cross-sectional studies; instead, it refers to the order of tasks in a study design.

Correct Answer: D

Rationale: Mr. Takashi should be allowed to participate in the study only if it is likely to benefit him directly. This decision aligns with the principle of beneficence in research ethics, which emphasizes maximizing benefits and minimizing risks for research participants. Since Mr. Takashi is incapable of giving consent, his participation should be based on the likelihood of direct benefits to him rather than solely for the benefit of others or solely for research purposes. Option A is too restrictive and does not consider potential benefits to Mr. Takashi. Option B is flawed as it disregards the need for the study to benefit Mr. Takashi. Option C focuses on benefiting others, which is not the primary consideration when the participant cannot give consent.