Choose Your Research Design  
Good statistical practice suggests that you choose your design before doing the experiment. So if you are in the planning stages of an experiment, go through the key below, and when you enter a specific DAWG module, use the provided example data to help fully understand how your experiment should be conducted, and what types of data need to be collected. Another very important aspect of planning an experiment is deciding how large the experiment needs to be. This falls under the topic of statistical power. Once you have decided on ANOVA or Regression methods (see 1 below), then go to the Examples tab and choose ANOVA power or Regression power links to learn about software tools for sample size determination. If you have data ready for analysis, go through the key below and you will be led to an appropriate DAWG module that will guide you in using SAS to analyze your data. Experimental Design Selection Key 1. Do you want to test for differences among treatment means?
For ANOVA, you may choose among seven experimental designs via this key. The choice you make below will lead you to pages that enable you to then choose among seven treatment designs, with the choice to further refine the analysis with any combination of three specialized features (or no specialized features).
2. Are you blocking on a factor?
3. Is your block too small to contain all treatments? 4. Does each block contain one and only one treatment? 5. At this point you should have two blocking factors, that we will call rows and columns. Why?
6. Do you have any other sources of variation besides rows and columns?
8. You have a Switchback Design (What is Switchback?) Last choice = Switchback: you should have rows and columns in a rectangular array, but you have an additional concern (as in red arrow 6) that row differences may differ for each column.


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