Dr. Samuelson wants to study the impact of social media on the friendships of 20-, 40-, 60-, and 80-year-olds. He plans to follow each age group for 10 years and study their use of social media and their relationships. What type of study is Dr. Samuelson conducting? A. Longitudinal study.
B. Cross-sequential study.
C. Normative study.
D. Cross-sectional study.

Dr. Samuelson is conducting a B. Cross-sequential study.

Explanation:

A Cross-sequential study is a mixture of the longitudinal and cross-sectional study.

Let's break them both down:

Thus, a cross-sequential study observes its various types of subjects through a long period of time.

It can be seen in this example: Dr. Samuelson's plan is to follow various subjects of different ages over 10 years in order to observe their use of social media and relationships.

european feudalism was a combination of legal and military customs in medieval europe that flourished between the 9th and 15th centuries. broadly defined, it was a way of structuring society around relationships derived from the holding of land in exchange for service or labour.

japanese feudalism. the era of feudalism in japan took place from the 12th through 19th centuries. during that period local rulers, either powerful families or military warlords, dominated the land, while the emperor was merely a figurehead and not a significant political presence.

they had freedom from the government and from the affairs