STATISTICAL APPLICATIONS, Experimental Design

title 'CRD, 4 trts, 3 reps';
data a;
do unit=1 to 12;
if (unit<=3) then treat=1;
if (unit>3<6) then treat=2;
if (unit>6<9) then treat=3;
if (unit>9<12) then treat=4;
output;
end;
proc plan seed=37255;
factors unit=12;
output data=a out =b;
proc sort; by unit;
proc print;
run;

Delete Function
If 1 <TRT<10 then delete;
(gets rid of trts 2-9 and keeps 1, 10, 11, 12, 13)

Program to output Transposed Data

data one;
input yr trt yield;
cards;
88        1          1000
88        2          2000
88        3          2400
89        1          4000
89        2          3200
89        3          3500
data two; set one;
proc sort; by trt yr;
proc transpose data = two out = three prefix = y ;
id yr;
var yield;
by trt;
proc print;
run;

Procedure for Determining Differences in Population Means

data one; input sample time $ ph P oc k;
cards;
1          A         6.17    21.47  0.924  150
2          A         6.27    18.69  0.939  139
3          B         6.16    21.20  1.042  142
4          B         5.65    41.74  1.054  144
proc ttest;
classes time;
var ph p k oc;
run;

Reliability

Estimated probabilities (reliabilities) of treatment (any treatment where a direct comparison can be made with a check) response compared to a check for the sample of treatment differences (years or locations) can be determined as defined by Eskridge and Mumm (1992) where: RNi = P(Z > - ydi/sdi) such that Z is a standard normal random variable and ydi and sdi are estimates of the sample mean difference and standard deviation, respectively.  A modified reliability estimate (economic reliability, REi) can be calculated by subtracting the costs (in yield units) of the fertilizer and its application from the mean difference for the ith treatment (di) against the treatment check as: REi = P(Z > -(ydi - ci)/ sdi) where ci represents the equivalent yield necessary to pay for the fertilizer and its application for a given price ratio.  These values are then substituted in the equation to calculate reliability for normally distributed differences.  The recalculated reliability represents the normal probability that a treatment will outperform the treatment check in a quantity superior to ci, therefore, providing an estimate of the economic feasibility of the practice as well as allowing direct comparisons of net benefits among calculated reliabilities for a given price ratio.