A researcher wishes to study developmental changes in the music people prefer to listen to. The researcher locates 50 people who are about 20 years old. She sends these people a questionnaire every year for the next 10 years asking about the types of music they prefer to listen to. This is an example of which type of design? A. Longitudinal B. Cross-Sectional

A. Longitudinal

Explanation:

Longitudinal design: In psychological research, the term longitudinal research is defined as a study that involves a particular variable or a specific group of variables possessing the similar subjects, cases, or participants for a specific period, it can even last for months or years.

A longitudinal study is also denoted as a panel study or longitudinal survey which involves the repetition of a particular variable's observation.

In the question above, the given statement is an example of a longitudinal design.

B. Cross-Sectional

Explanation:

A Cross-sectional study of design is a kind of design of observational study. In the cross-sectional study, an investigator measures or examines the outcome as well as the exposures in any study participants at the same time.

Cross-sectional design research includes using some different category of the people who differ in some variable of interest but they share few other characteristics, like educational background, socioeconomic status and ethnicity.

A Cross-sectional studies are mostly used by experimenters or researchers to study the developmental psychology in humans.

Thus in the context, the researcher using 50 participants to study the developmental changes in their choices to listen to music is a type of cross sectional research design.

Hence the correct option is (B).