The primary objective of sampling is to obtain information about a population with maximum effort. Sampling is a statistical technique used to collect data from a subset of individuals or items within a larger population. It is impractical and often impossible to collect data from an entire population, so sampling allows researchers to gather information from a smaller group that represents the larger population.

1. Definition of Sampling:
- Sampling is a statistical method that involves selecting a subset of individuals or items from a larger population in order to make inferences or draw conclusions about the entire population.
- The selected subset is called a sample, and the process of selecting the sample is known as sampling.

2. Purpose of Sampling:
- The primary purpose of sampling is to obtain information about a population without having to study or investigate every individual or item within that population.
- Sampling allows researchers to make inferences about the population based on the characteristics observed in the sample.

3. Advantages of Sampling:
- Saves time and resources: Sampling reduces the time and effort required to collect data by focusing on a smaller subset of the population.
- Cost-effective: Sampling is a cost-effective method compared to conducting a complete census of the population.
- Feasibility: Sampling makes it possible to collect data from populations that are large, dispersed, or difficult to access.
- Accuracy: Sampling techniques can provide accurate estimates of population parameters when properly designed and executed.

4. Maximum Effort in Sampling:
- When it is said that sampling aims to obtain information with maximum effort, it means that the sample should be selected in a way that maximizes the representativeness and accuracy of the information obtained.
- Maximum effort in sampling involves carefully designing the sampling method, selecting an appropriate sample size, and ensuring that the sample is representative of the population.

In conclusion, the primary objective of sampling is to obtain information about a population with maximum effort. This involves selecting a representative sample and ensuring that the sampling process is well-designed and executed to provide accurate estimates of population parameters.