2.42.1.2 Tutorial of Power and Sample Size in DOE

DOE App Updates for OriginPro 2024

Summary

Before running an experiment, it is important to know whether your design has enough data to detect the effects you care about. Power analysis helps answer this question: given factors, effect size, and variability, how many replicates do you need to achieve a desired statistical power?

This tutorial shows how to perform a power and sample size calculation for a 2-level factorial design using the Design of Experiments app. You will set up a full factorial design with three factors and two blocks, then determine the number of replicates required to reach a power of approximately 0.93 for an effect size of 0.4 with a standard deviation of 0.2.

Steps

1. Click the Design of Experiments icon in the Apps Gallery
2. Click the Power and Sample Size button
3. Select 2-Level Factorial. In the Design tab, select 3 from Number of Factors drop-down list. Choose Full factorial from Fraction drop-down list. Select 2 for Number of Blocks. Enter 0 in Number of Terms Omitted from Model. Turn in Include Blocks in Model button.

   

4. In the Settings tab, choose Power to calculate. Click plus button to add 1 level to Replicates and enter 1 and 2 in each level. Enter 0.4 in Effects. Enter 0 in Number of Center Points per Block. Enter 0.2 in Standard Deviation. Click OK.

   

5. The results in the report indicates that you should have 2 replicates in order to get a power value of 0.92679.