Hyper-Graeco-Latin square design

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In the design of experiments, hyper-Graeco-Latin squares are efficient designs to study the effect of one primary (treatment) factor in the presence of 4 blocking (nuisance) factors. They are restricted, however, to the case in which all the factors have the same number of levels.

Designs for 4- and 5-level factors are given in this article. These designs show what the treatment combinations should be for each run. When using any of these designs, the treatment units and trial order should be randomized as much as the design allows. For example, one recommendation is that a hyper-Graeco-Latin square design be randomly selected from those available, then randomize the run order.

There are no 3-level factor hyper-Graeco Latin square designs.

Contents

[edit] Design for 4-level factors

For 4-level factors, the design consists of sixteen runs:

X1:
row blocking factor
X2:
column blocking factor
X3:
blocking factor
X4:
blocking factor
X5:
treatment factor
1 1 1 1 1
1 2 2 2 2
1 3 3 3 3
1 4 4 4 4
2 1 4 2 3
2 2 3 1 4
2 3 2 4 1
2 4 1 3 2
3 1 2 3 4
3 2 1 4 3
3 3 4 1 2
3 4 3 2 1
4 1 3 4 2
4 2 4 3 1
4 3 1 2 4
4 4 2 1 3

This can alternatively be represented as (A, B, C, and D represent the treatment factor and 1, 2, 3, and 4 represent the blocking factors):

A11 B22 C33 D44
C42 D31 A24 B13
D23 C14 B41 A32
B34 A43 D12 C21

[edit] Design for 5-level factors

For 5-level factors, the design consists of twenty-five runs:

X1:
row blocking factor
X2:
column blocking factor
X3:
blocking factor
X4:
blocking factor
X5:
treatment factor
1 1 1 1 1
1 2 2 2 2
1 3 3 3 3
1 4 4 4 4
1 5 5 5 5
2 1 2 3 4
2 2 3 4 5
2 3 4 5 1
2 4 5 1 2
2 5 1 2 3
3 1 3 5 2
3 2 4 1 3
3 3 5 2 4
3 4 1 3 5
3 5 2 4 1
4 1 4 2 5
4 2 5 3 1
4 3 1 4 2
4 4 2 5 3
4 5 3 1 4
5 1 5 4 3
5 2 1 5 4
5 3 2 1 5
5 4 3 2 1
5 5 4 3 2

This can alternatively be represented as (A, B, C, D, and E represent the treatment factor and 1, 2, 3, 4, and 5 represent the blocking factors):

A11 B22 C33 D44 E55
D23 E34 A45 B51 C12
B35 C41 D52 E31 A24
E42 A53 B14 C25 D31
C54 D15 E21 A32 B43

[edit] See also

[edit] External links

[edit] References

  • (1978) Statistics for Experimenters: An Introduction to Design, Data Analysis, and Model Building. John Wiley and Sons. 

This article incorporates text from a public domain publication of the National Institute of Standards and Technology, a U.S. government agency.