Jade spent two years in a Mexican-American community studying communication between parents and children. Jade was using __________.

Correct Answer: B

Rationale: Jade was using ethnography. Ethnography involves the systematic study of people and cultures through participant observation and interviews. In this case, Jade spent two years in a Mexican-American community studying communication between parents and children, which aligns with the methodology of ethnography. Ethnography allows researchers to gain an in-depth understanding of a particular cultural group's behaviors, practices, and beliefs. Choice A, naturalistic observation, involves observing subjects in their natural environment without interference or manipulation. While similar to ethnography in some aspects, naturalistic observation does not typically involve the same level of cultural immersion and participant interaction as ethnography. Choice C, self-reports, refers to data collected directly from participants about their thoughts, feelings, or behaviors. This method relies on participants' subjective responses and may not provide the same depth of cultural insights as ethnography. Choice D, structured observation, involves observing behavior in a structured and controlled environment. Unlike ethnography, structured observation does not focus on the cultural nuances and immersive study of a specific community.

Correct Answer: B

Rationale: In an experiment, the independent variable is the one that the investigator expects to cause changes in another variable. It is the factor that is deliberately manipulated or changed by the researcher to observe its effects on the dependent variable. The purpose of manipulating the independent variable is to study its impact on the outcome, allowing researchers to establish cause-and-effect relationships in their investigations. Choice A is incorrect because the independent variable is not influenced but rather influences another variable. Choice C is incorrect as the independent variable is intentionally manipulated by the researcher. Choice D is incorrect as it refers to a different concept unrelated to the independent variable in an experiment.

Correct Answer: C

Rationale: In field experiments, researchers randomly assign participants to treatment conditions in natural settings. This method allows for a higher level of control over potential confounding variables compared to non-random assignment. Random assignment helps ensure that the groups being compared are comparable at the beginning of the study, which strengthens the internal validity of the research findings. Choice A is incorrect because selective assignment may introduce bias. Choice B is incorrect as researchers can use random assignment in field experiments. Choice D is incorrect because field experiments typically have less control over the treatment compared to laboratory experiments.

Correct Answer: A

Rationale: A major strength of the longitudinal design is that researchers can examine relationships between early and later behaviors. This design allows researchers to observe and track changes in the same participants over an extended period of time, providing valuable insights into developmental trajectories and how behaviors are connected across different stages of life. Choice B is incorrect because longitudinal studies track changes over time, not necessarily collect a large amount of data in a short time span. Choice C is incorrect as it refers to cross-sectional studies rather than longitudinal studies. Choice D is incorrect as it describes a cross-sectional design where participants of different ages are studied at the same time.

Correct Answer: C

Rationale: One major disadvantage of cross-sectional research is that factors affecting individual development cannot be explored thoroughly. Cross-sectional research involves comparing different groups of people at one specific point in time, and does not allow for tracking individual changes over time. This limitation means that the unique influences and trajectories of individual development may be overlooked in cross-sectional studies. Choices A, B, and D are incorrect. Choice A is not a major disadvantage of cross-sectional research as age-related changes can still be compared across different groups in this type of study. Choice B, while a potential issue in any study, is not specific to cross-sectional research. Choice D refers to a different type of bias caused by repeated testing rather than a major disadvantage of cross-sectional research.