Free statistical calculators online. Our basic statistical calculators will help you in common tasks you might encounter and deal mostly with simple distributions.
Free statistical calculators online. Our basic statistical calculators will help you in common tasks you might encounter and deal mostly with simple distributions.
This handout lists the most commonly used effect sizes, adjustments, and rules of thumb concerning sample size calculation.
G*Power is a tool to compute statistical power analyses for many different t tests, F tests, χ2 tests, ztests and some exact tests. G*Power can also be used to compute effect sizes and to display graphically the results of power analyses.
An important idea in statistics is that the amount of data matters. We often teach this with formulas --- the standard error of the mean, the t-statistic, etc. --- in which the sample size appears in a denominator as √n. This is fine, so far as it goes, but it often fails to connect with a student's intuition. In this presentation, I'll describe a kinesthetic learning activity --- literally a random walk --- that helps drive home to students why more data is better and why the square-root arises naturally and can be understood by simple geometry. Students remember this activity and its lesson long after they have forgotten the formulas from their statistics class.
Calculate the number of respondents needed in a survey using our free sample size calculator. Our calculator shows you the amount of respondents you need to get statistically significant results for a specific population. Discover how many people you need to send a survey invitation to obtain your required sample. You can also calculate the margin of error based on your sample size.
This is an online calculator that can be used to determine the recommended sample size that is needed for a specific margin of error, confidence level, and population size.