The PLAN Procedure

Three Replications with Four Factors

(View the complete code for this example.)

Suppose you want to determine if the order in which four drugs are given affects the response of a subject. If you have only three subjects to test, you can use the following statements to design the experiment.

proc plan seed=27371;
   factors Replicate=3 ordered Drug=4;
run;

These statements produce a design with three replicates of the four levels of the factor Drug arranged in random order. The three levels of Replicate are arranged in order, as shown in Figure 87.1.

Figure 87.1: Three Replications and Four Factors

The PLAN Procedure

FactorSelectLevelsOrder
Replicate33Ordered
Drug44Random

ReplicateDrug
13241
21243
34123


You might also want to apply one of four different treatments to each cell of this plan (for example, applying different amounts of each drug). The following additional statements create the output shown in Figure 87.2:

   factors Replicate=3 ordered Drug=4;
   treatments Treatment=4;
run;

Figure 87.2: Using the TREATMENTS Statement

The PLAN Procedure

Plot Factors
FactorSelectLevelsOrder
Replicate33Ordered
Drug44Random

Treatment Factors
FactorSelectLevelsOrder
Treatment44Random

ReplicateDrugTreatment
131242134
243214123
332411423