# Sample Size Determination

• ### Collection: Statistical Calculators

Free statistical calculators online.  Our basic statistical calculators will help you in common tasks you might encounter and deal mostly with simple distributions.

• ### Analysis Tool: G*Power (Statistical Power Analyses)

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.

• ### Effect and Sample Size

This handout lists the most commonly used effect sizes, adjustments, and rules of thumb concerning sample size calculation.

• ### Sample Size Determination In Research

This is a complete lesson module (including example problems with answers to selected problems) for the purpose of enabling students to: 1) Provide examples demonstrating how the margin of error, effect size, and variability of the outcome affect sample size computations. 2) Compute the sample size required to estimate population parameters with precision. 3) Interpret statistical power in tests of hypothesis. 4) Compute the sample size required to ensure high power when hypothesis testing.
• ### Power and Sample Size Determination

Powerpoint explaining what power is and how power and sample size are related to one another.
• ### Sample size calculation

A resource providing information about what the sample size is, what factors the sample size depends on, and how it can be determined,
• ### Sample Sizes Required

Resource providing information about: computation of the sample size and the assumptions that must be made to do so. Several examples are given with different conditions in each, and a table showing minimum sample sizes for a two-sided test.
• ### Statistical Significance and Sample Size

Article that explains why comparing statistical significance, sample size and expected effects are important before constructing and experiment.
• ### Sample Size Calculator

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.

• ### Sample Size Calculator

An online calculator designed to give an estimated sample size that would be needed under specific conditions. This is used only for simple random samples.