Network sampling is a type of sampling method that is used in research to study the characteristics and behavior of a particular group or population within a social network. This method involves selecting a sample of individuals from a larger network, and collecting data on their relationships and interactions with other members of the network. The goal of network sampling is to understand the patterns and dynamics of social interactions within a group or population, and to identify the factors that influence these interactions.

One example of network sampling is the use of snowball sampling in social media research. Snowball sampling involves starting with a small group of individuals, and asking them to refer other members of the network who may be interested in participating in the study. This method is particularly useful for studying networks that are difficult to access or locate, such as online social networks or hidden populations. For example, a researcher studying the use of social media among teenagers may use snowball sampling to recruit participants from popular social media platforms like Instagram or Snapchat. By starting with a small group of teens who are active on these platforms, the researcher can then ask them to refer other teens who may be interested in participating in the study.

Another example of network sampling is the use of respondent-driven sampling (RDS) in research on hidden populations, such as drug users or sex workers. RDS involves recruiting a small group of individuals from the target population, and asking them to refer other members of the population to the study. This method allows researchers to access hard-to-reach populations that may not be easily identified through traditional sampling methods, and to study the social networks and behaviors of these groups. For example, a researcher studying the use of intravenous drugs among young adults in a city may use RDS to recruit participants from this hidden population. By starting with a small group of drug users, the researcher can then ask them to refer other users to the study, and use the data collected to understand the patterns and dynamics of drug use within this group.

Network sampling has a number of advantages over traditional sampling methods, including the ability to study the social interactions and relationships within a group or population, and the ability to access hard-to-reach populations. However, there are also some limitations to this method, including the potential for bias in the sample selection process, and the need for careful data collection and analysis to ensure the accuracy and reliability of the results. 

Overall, network sampling is a useful tool for researchers studying the behavior and characteristics of groups and populations within social networks, and can provide valuable insights into the patterns and dynamics of social interactions and relationships.