Defining Your Sample Size

[benf]

A more in-depth answer can be found here! Mainly depends on the desired percentage of confidence, desired percentage of reliability, and the type of data being collected from the samples.

How do you calculate the correct sample size for reliability testing?

You’ll often hear that a sample size of n = 30 should be your minimum target. This should be understood that you need 30 minimum samples before you can expect a z-test analysis (normal distribution) to be valid. A z-test is used in hypothesis testing to evaluate whether a finding or association is statistically significant or not . This rationale comes from the Central Limit Theorem to approximate the sample distributions. As a general rule of thumb from Anna-Katrina Shedletsky’s article: Ex…