Population
Population refers to a group of people, events, or things of interest that a researcher wishes to investigate. Statistically, population is any complete group of items with at least one characteristic in common. It is also called a universe. Sociologists define population as the totality of human beings.
Sample
A sample is subgroup of the population. It comprises of some of the items selected from the population. Statistics calculated from samples collected are used to make inferences about the population. A sample is usually collected randomly or systematically from the population using different methods. The researcher is able to draw conclusions about the population by studying the sample.
Importance of sample size
A sample size allows the researcher to minimize the probability of reporting false findings. Increased number of variables in a research increases the number of conflicting findings and developments. Sample size helps describe the variables in a particular group. This reduces the risk of making high statistical error in statistical calculations.
Sample size has a feature about making assumptions about the population from a sample. Sample size relies on data collected. For instance, in a survey sampling there are different sample sizes for every population. For the census, data is collected from the whole population; hence the sample size estimates the size of the population.
Understanding sample size is essential for the interpretation of the findings. When studying sample size one should establish an acceptable level of statistical importance. Sample size ensures an effective allocation of resources. It also ensures there is a high probability of detecting a statistically significant result, hence effective allocation of resources.
