In: Psychology
Describe the difference between a "population" and a "sample." What is a "representative sample" 1 What is the best way to achieve representativeness in a sample?
In a research study, the researcher aims to study a certain phenomenon on a particular group, this group consists of all the persons belonging to that particular population. As it is not possible to study all the members of that particular group, the researcher has to take in some people who are part of that group. Sample is the participants who are part of a particular population, they represent the population. If a population is diverse in nature then the sample should also be diverse and accurately represent the population.
Representative sample means that the sample should accurately represent the population. If a researcher is studying the anxiety levels of people with short heights, then the population of this study is all the people in the world with short height. But, as it is not possible to take all the people for the study, a sample is chosen to represent the data. So, the sample should consists of people with short height.
The best way to accurately represent the population is to take the sample which reflects the population. So, choosing people from one college or one place would not accurately represent the data. Instead, many geographic location could be picked, and also many groups and occupation of people with short height could be picked to accurately represent the population.
Another Example - A correlational study is done to find the association between physical exercise and its effect on hypertension patients. Here, the population is all the hypertension patients, so in order to accurately represent the population, a sample of hypertension patients is taken from a hospital by setting some exclusion criteria such as co-morbidity, as taking in co-morbid patients will not represent the hypertension population