Average Sample Number (ASN) is a statistical measure used to determine the average number of samples needed to obtain a specified level of accuracy in a sample survey. It is calculated by dividing the total number of samples by the total number of units in the population.

For example, if a population consists of 100 units and a sample size of 10 is selected, the ASN would be 10/100 = 0.1. This means that, on average, 0.1 samples are needed to obtain a specified level of accuracy in the sample survey.

ASN is an important measure for sample surveys because it helps researchers determine the appropriate sample size for their study. The larger the ASN, the more samples are needed to obtain a specified level of accuracy. This is because larger samples provide more information and are less subject to random error.

There are several factors that can affect the ASN in a sample survey. These include the size of the population, the level of accuracy desired, and the sampling method used.

The size of the population is an important factor in determining the ASN. In general, the larger the population, the larger the sample size that is needed to obtain a specified level of accuracy. This is because larger populations are more diverse and contain more variability, which makes it more difficult to obtain accurate results.

The level of accuracy desired is another important factor in determining the ASN. Researchers often use a measure called the confidence level to specify the level of accuracy desired in a sample survey. The confidence level is the probability that the sample results will be within a certain margin of error of the true population value. For example, a confidence level of 95% means that the sample results will be within a certain margin of error of the true population value 95% of the time. The higher the confidence level, the larger the sample size that is needed to obtain the desired level of accuracy.

The sampling method used is also an important factor in determining the ASN. Different sampling methods have different levels of accuracy and require different sample sizes to obtain a specified level of accuracy. For example, simple random sampling is a widely used sampling method that involves selecting a random sample from the population. This method is relatively simple and provides a good level of accuracy, but it requires a larger sample size than other sampling methods.

In summary, the Average Sample Number is a statistical measure used to determine the average number of samples needed to obtain a specified level of accuracy in a sample survey. It is calculated by dividing the total number of samples by the total number of units in the population. ASN is an important measure for sample surveys because it helps researchers determine the appropriate sample size for their study.