Experimental Design
So Far In Experimental Design Single replicate Designs. Completely Randomized Blocks. Randomized Complete Blocks. Latin Square Designs. Lattice Square Designs. Rectangular Lattice Designs.
Two, or more, factor designs
Multiple Factor Designs An organism may vary in one factor according to conditions set by another factor. Single factor experiments have limitations as they only relate to the conditions under which the factor is examined.
Multiple Factor Designs Examine the effect of differences between factor 1 levels. Examine the effect of differences between factor 2 levels. Examine the interaction between factor 1 levels and factor 2 levels.
Interactions GenotypeNitrogen 1Nitrogen 2 A3,4684,088 B2,5044,791 A B
Interactions Low NHigh N A B Yield
Interactions Low NHigh N A B Yield
Interactions Low NHigh N A B Yield
Split-Plot Designs Factorial Designs Strip-plot Designs
Factorial Experimental Designs Experimental design where all possible combinations of levels from two (or more) factors is called a factorial design. Factorial designs are usually balanced, but unbalanced designs are possible (but not advised).
Factors Species Genotype Nutrient Water Soil type Seeding time Seeding rate Intercepted radiation Day length Location Temperature Feed stock Tillage Machinary
Factorial Experimental Design Irrigation Days between defoliation dayI1.D0I1.D4I1.D8I1.D12 2 dayI2.D0I2 D4I2D8I2D12 3 dayI3.D0I3.D4I3D8I3D12
3 t21 t13 t32 t41 t33 t4 3 t12 t21 t42 t11 t22 t3 3 t31 t22 t21 t33 t43 t1 2 t33 t21 t12 t44 t11 t4 1 t23 t12 t11 t12 t43 t2 1 t33 t32 t23 t41 t42 t3 I II III Factorial Experimental Design
Two-Factor Factorial Model Y ijk = + r i + d j + w k + dw jk + e ijk Where Y ijk is the performance of the the j th replicate, and the j th d factor and k th w factor; in the overall mean; r j is the effect of the j th replicate; d i is the effect of the i th d-factor; w k is the effect of the k th w-factor; dw jk is the interaction effect between d j and w k ; and e ijk is the error term.
Three-Factor Factorial Model Y ijk = +r i +d j +w k +g l +dw jk +dg jl +wg kl +dwg jki +e ijk Where Y ijk is the performance of the the j th replicate, and the j th d factor and k th w factor and l th g-factor; in the overall mean; r j is the effect of the j th replicate; d i is the effect of the i th d-factor; w k is the effect of the k th w-factor; gl is the effect of the l th g-factor ; dw jk is the interaction effect between d j and w k ; dg jl is the interaction effect between d j and w l ; wg jl is the interaction effect between w k and g l ; dwg jkl is the interaction effect between d j, w k and g l ; and e ijk is the error term.
Factorial Experimental Designs Can be used with any number of factors and factor levels. Gives equal precision to estimating all factors and levels. Greatest mistake by researchers is to include too many factors where interpretation of three-way interactions can be difficult.
Split-Plot Designs Three irrigation treatments Four cultivars. Two seeding rates (HIGH and low)
Split-Plot Designs III
III
aCdB AcDb III
aCdBDCbA AcDbdcba CbaDDcBA cBAddCba dabCbcDA DABcBCda III
Greater precision of measurement is required on one of the factors (assigned to sub-plots). Less precision required on the other factor (assigned to main-plots). The relative size of the main effect of two factors is different. Management practices do not allow factorial designs.
Main Plots Split-Plot Design
1 423 Main Plots Split-Plot Design
Main Plots Split-Plot Design
1B1B 1A1A 1C1C 1D1D 4B4B 4C4C 4A4A 4D4D 2D2D 2C2C 2A2A 2B2B 3D3D 3B3B 3C3C 3A3A Main Plots Sub-Plots Split-Plot Design
AABA BBAB ABBA BAAB BBAA AABB BABB ABAA I II III IV Split-Plot Design
I B A C II C A B III B A C Split-Plot Design
Split-Split-Plot Design
MP.3 MP.4 MP.1 MP.2 Split-Split-Plot Design
MP.3 MP.4 MP.1 MP.2 SP.1 SP.2 SP.1 SP.2 SP.1 SP.2 Split-Split-Plot Design
SSP.3SSP.1SSP.2SSP.4 MP.3 MP.4 MP.1 MP.2 SP.1 SP.2 SP.1 SP.2 SP.1 SP.2 Split-Split-Plot Design
SSP.3SSP.1SSP.2SSP.4 SSP.1SSP.4SSP.3SSP.2 SSP.3SSP.4SSP.1 SSP.4SSP.1SSP.3SSP.2 SSP.3SSP.2SSP.1SSP.4 SSP.2SSP.4SSP.3SSP.1 SSP.4SSP.1SSP.2SSP.3 SSP.4SSP.2SSP.3SSP.1 MP.3 MP.4 MP.1 MP.2 SP.1 SP.2 SP.1 SP.2 SP.1 SP.2 Split-Split-Plot Design
Split-Plot Design Model Y ijk = + r i + g j + e(1) ij + t k + gt jk + e(2) ijk
Split-Plot Design Model Y ijk = + r i + g j + e(1) ij + t k + gt jk + e(2) ijk
Split-Plot Design Model Y ijk = + r i + g j + e(1) ij + t k + gt jk + e(2) ijk Where Y ijk is the performance of the the j th replicate, and the j th main-plot and k th sub-plot; in the overall mean; r j is the effect of the j th replicate; g i is the effect of the i th main-plot; e(1) ij is the main-plot error; t k is the effect of the k th sub-plot; gt jk is the interaction effect between g j and t k ; and e(2) ijk is the sub-plot error term.
B A C A C B Strip-Plot Design I II III IV
B A C II A C B B A C IV A C B Strip-Plot Design III IV I II
B A C A C B IV III I II B A C A C B Strip-Plot Design
B A C A C B IV III I II B A C A C B Strip-Plot Design
B A C A C B IV III I II B A C A C B Strip-Plot Design 1
Strip-Plot Design Model Y ijk = +r i +g j +e(g) ij +t k +e(t) ij +gt jk +e(gt) ijk Where Y ijk is the performance of the the j th replicate, and the j th strip and k th strip; in the overall mean; r j is the effect of the j th replicate; g i is the effect of the i th strip-plot; e(g) ij is the g- factor error; t k is the effect of the k th strip-plot; e(t) ij is the t-factor error; dw jk is the interaction effect between g j and t k ; and e(gt) ijk is the sub- plot error term.
Restraints