Sample size determination is the process of selecting the number of observations that are included in statistical sample. Sample size can be said as an important aspect of empirical stud, where the researcher needs to make inferences about population from a sample. If we have a look at the practical application, sample size that is in a study is influenced by considering the expense of data collection. Sometimes, the need to having enough statistical powers in complicated studies give rise to a number of sample sizes. Sample size can be estimated by using the below methods –
- By using target variance that is to be derived from the sample.
- Using readily available or collected data
- Using the target of the statistical test, after the sample gets collected.
In order to determine the sample size during statistical analysis, researchers can take Dissertation statistics help that is provided by various dissertation writing firms. Estimating the proportion is one of the simple situation in which the sample size is determined. One of the common problems that are faced by the researchers during sample size determination is yielding a specific power for the test and giving the error rate. Large sample size will definitely lead to precision, especially, when estimating with the help of unknown parameters. While in some situations, the accuracy for large sample sizes is minimum and. This will result in presence of dependency of data and systematic errors.
Usually, the sample sizes are determined on the basis of quality of the estimated result. The sample size can also be assessed on the basis of power of hypothesis test. One may have 80% of the power to detect the difference in support levels. With the increase in number of Statistics Consultation firms, the demand of sample size determination also increased. In order to determine the sample size, the researchers started taking the help of these firms. To get full assistance from these firms, the researcher should provide them with all the relevant data, objective of the research and results, so that the researcher can make much out of their work. To determine the sample size the researcher need to follow five steps which are as below –
- Determining the goals.
- Determining the desired results
- Finding the confidence level
- Calculating the degree of reliability
- Estimating the response rate.
Hence, by following the above steps, one can determine the sample size easily.