What Is a Good Statistical Sample Size?


Quick Answer

A good statistical sample size is at least 100, and preferably more, participants. With a 100-participant sample size, the researcher has a margin of error of approximately 10 percent with a 95 percent confidence rating in the results. For the researcher to increase his confidence rating and reduce his margin of error he has to increase the size of the sample.

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What Is a Good Statistical Sample Size?
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Full Answer

The more the sample size increases, the more the margin of error decreases. This is because by surveying a larger sample of people, the researcher is more likely to receive results that complement the viewpoint of the general population. By utilizing a smaller sample size, the researcher is skewing his results by basing them on the statistics given to him by a small percent of the population. The researcher's confidence rating is his guide to the probability of how accurate his research is. Most researchers utilize a 95 percent correct confidence level when conducting statistical research. An example is if the researcher surveys 500 people, his margin of error is 4.5 percent with a 95 percent confidence level. This means if 50 percent of the surveyed people choose A instead of B, the researcher can say with 95 percent confidence that between 45.5 percent and 55.5 percent of the population prefer A over B.

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