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This guide emphasizes the fundamental principles of experimental design: Replication, Randomization, and Blocking. It explains how these concepts enhance the design and analysis of experiments to obtain valid results. The text further covers methods for fitting values and the importance of degrees of freedom in analysis. With practical examples and straightforward explanations, this resource serves as an essential tool for researchers aiming to design effective experiments while maintaining simplicity. Understand how to implement these principles in your experimental work.
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Quantitative Methods Designing experiments - keeping it simple
Designing experiments - keeping it simple Three principles of experimental design • Replication • Randomisation • Blocking
Designing experiments - keeping it simple Three principles of experimental design
Designing experiments - keeping it simple Three principles of experimental design Design and analysis • Replication • Degrees of freedom
Designing experiments - keeping it simple Three principles of experimental design • Replication • Randomisation • Blocking
Designing experiments - keeping it simple Three principles of experimental design
Designing experiments - keeping it simple Three principles of experimental design Unit Tr RandTr 1 A 2 A 3 A 4 A 5 B 6 B 7 B 8 B 9 C 10 C 11 C 12 C 13 D 14 D 15 D 16 D sample 16 Tr RandTr
Designing experiments - keeping it simple Three principles of experimental design Unit Tr RandTr 1 A C 2 A B 3 A D 4 A B 5 B B 6 B A 7 B D 8 B A 9 C D 10 C B 11 C A 12 C C 13 D C 14 D D 15 D C 16 D A sample 16 Tr RandTr
Designing experiments - keeping it simple Three principles of experimental design Design and analysis • Replication • Randomisation • Degrees of freedom • Valid estimate of EMS
Designing experiments - keeping it simple Three principles of experimental design
Designing experiments - keeping it simple Three principles of experimental design Design and analysis • Replication • Randomisation • Degrees of freedom • Valid estimate of EMS
Designing experiments - keeping it simple Three principles of experimental design • Replication • Randomisation • Blocking
Designing experiments - keeping it simple Three principles of experimental design
Designing experiments - keeping it simple Three principles of experimental design
Designing experiments - keeping it simple Three principles of experimental design
Designing experiments - keeping it simple Three principles of experimental design Design and analysis • Replication • Randomisation • Blocking • Degrees of freedom • Valid estimate of EMS • Elimination
Designing experiments - keeping it simple Fitted values and models
Designing experiments - keeping it simple Fitted values and models
Designing experiments - keeping it simple Fitted values and models Term Coef Constant 16.6750 BLOCK 1 0.0417 2 2.3917 3 -1.4750 BEAN 1 5.0750 2 5.7000 3 -0.6000 4 -0.2500 5 -3.7000
Designing experiments - keeping it simple Fitted values and models Term Coef Constant 16.6750 BLOCK 1 0.0417 2 2.3917 3 -1.4750 BEAN 1 5.0750 2 5.7000 3 -0.6000 4 -0.2500 5 -3.7000 16.6750 +
Designing experiments - keeping it simple Fitted values and models Term Coef Constant 16.6750 BLOCK 1 0.0417 2 2.3917 3 -1.4750 BEAN 1 5.0750 2 5.7000 3 -0.6000 4 -0.2500 5 -3.7000 BLOCK 16.6750 + 1 0.0417 + 2 2.3917 3 -1.4750 4 -0.9584
Designing experiments - keeping it simple Fitted values and models Term Coef Constant 16.6750 BLOCK 1 0.0417 2 2.3917 3 -1.4750 BEAN 1 5.0750 2 5.7000 3 -0.6000 4 -0.2500 5 -3.7000 BEAN 1 5.0750 BLOCK 2 5.7000 16.6750 + 1 0.0417 + 3 -0.6000 2 2.3917 4 -0.2500 3 -1.4750 5 -3.7000 4 -0.9584 6 -6.2250
Designing experiments - keeping it simple Fitted values and models Term Coef Constant 16.6750 BLOCK 1 0.0417 2 2.3917 3 -1.4750 BEAN 1 5.0750 2 5.7000 3 -0.6000 4 -0.2500 5 -3.7000 BEAN 1 5.0750 BLOCK 2 5.7000 16.6750 + 1 0.0417 + 3 -0.6000 2 2.3917 4 -0.2500 3 -1.4750 5 -3.7000 4 -0.9584 6 -6.2250 So the fitted value for a plot in Block 2 planted with bean variety 6 is
Designing experiments - keeping it simple Fitted values and models Term Coef Constant 16.6750 BLOCK 1 0.0417 2 2.3917 3 -1.4750 BEAN 1 5.0750 2 5.7000 3 -0.6000 4 -0.2500 5 -3.7000 BEAN 1 5.0750 BLOCK 2 5.7000 16.6750 + 1 0.0417 + 3 -0.6000 2 2.3917 4 -0.2500 3 -1.4750 5 -3.7000 4 -0.9584 6 -6.2250 So the fitted value for a plot in Block 2 planted with bean variety 6 is 16.6750+
Designing experiments - keeping it simple Fitted values and models Term Coef Constant 16.6750 BLOCK 1 0.0417 2 2.3917 3 -1.4750 BEAN 1 5.0750 2 5.7000 3 -0.6000 4 -0.2500 5 -3.7000 BEAN 1 5.0750 BLOCK 2 5.7000 16.6750 + 1 0.0417 + 3 -0.6000 2 2.3917 4 -0.2500 3 -1.4750 5 -3.7000 4 -0.9584 6 -6.2250 So the fitted value for a plot in Block 2 planted with bean variety 6 is 16.6750+2.3917+
Designing experiments - keeping it simple Fitted values and models Term Coef Constant 16.6750 BLOCK 1 0.0417 2 2.3917 3 -1.4750 BEAN 1 5.0750 2 5.7000 3 -0.6000 4 -0.2500 5 -3.7000 BEAN 1 5.0750 BLOCK 2 5.7000 16.6750 + 1 0.0417 + 3 -0.6000 2 2.3917 4 -0.2500 3 -1.4750 5 -3.7000 4 -0.9584 6 -6.2250 So the fitted value for a plot in Block 2 planted with bean variety 6 is 16.6750+2.3917+(-6.2250)
Designing experiments - keeping it simple Fitted values and models Term Coef Constant 16.6750 BLOCK 1 0.0417 2 2.3917 3 -1.4750 BEAN 1 5.0750 2 5.7000 3 -0.6000 4 -0.2500 5 -3.7000 BEAN 1 5.0750 BLOCK 2 5.7000 16.6750 + 1 0.0417 + 3 -0.6000 2 2.3917 4 -0.2500 3 -1.4750 5 -3.7000 4 -0.9584 6 -6.2250 So the fitted value for a plot in Block 2 planted with bean variety 6 is 16.6750+2.3917+(-6.2250) = 12.7817 Advantages of mean and differences
Designing experiments - keeping it simple Orthogonality
Designing experiments - keeping it simple Orthogonality
Designing experiments - keeping it simple Orthogonality
Designing experiments - keeping it simple Orthogonality
Designing experiments - keeping it simple Orthogonality
Designing experiments - keeping it simple Orthogonality
Designing experiments - keeping it simple Orthogonality Design and analysis • Replication • Randomisation • Blocking • Orthogonality • Degrees of freedom • Valid estimate of EMS • Elimination • Seq=Adj SS
Designing experiments - keeping it simple Last words… • Experiments should be designed and not just happen • Think about reducing error variation and • replication: enough separate datapoints • randomisation: avoid bias and give separateness • blocking: managing the unavoidable error variation • The statistical ideas we’ve been learning so far in the course help us to understand experimental design and analysis Next week: Combining continuous and categorical variables Read Chapter 6