Correct Answer: C

Rationale: In a structured observation, each participant has an equal opportunity to display the behavior of interest because the researcher designs a specific set of conditions or tasks for all participants to engage in, providing a standardized environment for observation. This allows for fair and equitable observations across all participants, ensuring that each individual has the same opportunities to exhibit the behavior being studied. Choice A, clinical interview, typically involves a one-on-one interaction between a researcher and a participant focusing on collecting information through questions and answers, not providing equal opportunities for behavior display. Choice B, naturalistic observation, involves observing individuals in their natural environment without intervention or manipulation of conditions, which may not always ensure equal opportunities for behavior display. Choice D, case study, focuses on in-depth analysis of a single individual or a small group, providing detailed information but not necessarily ensuring equal opportunities for behavior display among participants.

Correct Answer: B

Rationale: The statement that is true about the Nurse-Family Partnership is that one of its goals is to promote competent early caregiving. The program provides support and guidance to first-time mothers to help them develop their caregiving skills and promote healthy child development. Choice A is incorrect because the program focuses on promoting healthy child development and supporting mothers, not specifically reducing the risk of teratogens. Choice C is incorrect because the Nurse-Family Partnership is not a series of childbirth classes but a program that involves home visits and support. Choice D is incorrect because the program's main focus is on supporting mothers in caregiving and child development, not primarily on family planning and genetic counseling.

Correct Answer: C

Rationale: The correct answer is C: longitudinal. In a longitudinal design, participants are followed and studied over an extended period, allowing researchers to observe changes and continuity in development as individuals age. This design is crucial for understanding how individuals grow and change over time. Cross-sectional studies (Choice A) involve comparing different groups at the same time point, while experimental studies (Choice B) involve manipulating variables to observe their effects. Correlational studies (Choice D) examine relationships between variables but do not involve studying participants over time.

Correct Answer: B

Rationale: By using random assignment of participants to treatment conditions, investigators increase the chances that participants' characteristics will be equally distributed across treatment groups. Random assignment helps reduce the likelihood of bias in the selection process and ensures that any differences between groups are due to the treatment and not pre-existing group differences. Sequential, systematic, and correlational assignment methods do not provide the same level of assurance in distributing participants' characteristics equally across treatment groups.

Correct Answer: A

Rationale: Lev Vygotsky viewed cognitive development as a socially mediated process, emphasizing the role of social interactions and cultural influences in shaping a child's cognitive development. This is in contrast to Jean Piaget, who focused more on individual interactions with the environment. Vygotsky believed that cognitive development is significantly influenced by social interactions with others, highlighting the importance of collaborative learning and cultural context. Choices B, C, and D are incorrect as they do not align with Vygotsky's perspective on cognitive development.