Why use random sampling in research
Simple random sampling in research
Reliability refers to the extent to which the research measure is a consistent and dependable indicator of medical investigation. It is difficult to manage the large population. This sampling method is a very basic method of collecting the data. But if the researcher is inexperienced then the data collected may or may not be upto the mark. This article has been cited by other articles in PMC. Which test CT or blood test is easier, safer and acceptable for this study? Thus, the goal of sampling is to ensure that the sample group is a true representative of the population without errors. The generalizability of clinical research findings is based on multiple factors related to the internal and external validity of the research methods. Whilst simple random sampling is one of the 'gold standards' of sampling techniques, it presents many challenges for students conducting dissertation research at the undergraduate and master's level.
The degree to which the research truly measures what it intended to measure[ 4 ] determines the fundamentals of medical research. Read more about:. For example, it is possible though unlikely that if you toss a fair die ten times, all the tosses will come up six.
Designing a clinical study involves narrowing a topic of interest into a single focused research question, with particular attention paid to the methods used to answer the research question from a cost, viability and overall effectiveness standpoint.
A systematic random sample is one in which every kth item is selected. Since the population size is large in this type of sampling method there is no restriction on the sample size that needs to be created. Since we are interested in all of these university students, we can say that our sampling frame is all 10, students.
Simple Random Sampling Example An organization has employees. If as a researcher, you want to save your time and money simple random sampling is one of the best probability sampling methods that you can use. When you read a health study based on a random sample, be aware that the findings are based not on every single person in the population that fit certain criteria, but on a subset of subjects chosen to represent them.
Random number table Advantages of Simple Random Sampling If applied appropriately, simple random sampling is associated with the minimum amount of sampling bias compared to other sampling methods.
Explain and illustrate the procedure of selecting a random sample
Some diseases, such as migraine, may have a different profile when evaluated in the population than when evaluated in the hospital. Scarborough et al. It would be virtually impossible to interview each and every one of these people to find out if they drink, what types of alcohol they drink, how often, under what circumstances, how much a beer or two per week versus enough to get intoxicated every weekend , and so forth. Nonsampling errors are induced by data collection and processing problems, and include issues related to measurement, processing and data collection errors. It is practically not possible to study the thought process of every member of the population and derive interference from the study. In this method you will have to number each member of population in a consequent manner, writing numbers in separate pieces of paper. Simple Random Sampling in research Today, the market research projects are much larger and sometimes an indefinite number of item are involved. Further considerations in clinical research, such as the clinical setting, study design, selection criteria, data collection and analysis, are influenced by the disease characteristics, prevalence, time availability, expertise, research grants and several other factors. Stratified random sampling such as this can be used to ensure that sampling adequately reflects the nature of current practice such as practice and management trends across the range of hospital patient volumes, for instance. Which procedure is going to be more expensive? However, we could have also determined the sample size we needed using a sample size calculation, which is a particularly useful statistical tool. Each element is marked with a specific number suppose from 1 to N. Important elements of dissertations such as research philosophy, research approach, research design, methods of data collection and data analysis are explained in this e-book in simple words. For any type of research on a population, using a representative sample to make inferences and generalizations about the larger group is critical; a biased sample can lead to incorrect conclusions being drawn about the larger population.
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