Page 276 - Area 9 - Relevant Document

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each row and
column

Error Maximum Some lost to blocks Some lost to rows
degree of and columns
freedom

Highly Can not be handle Takes care of Takes care of
variable the variability variability in one variability in two
eu’s direction direction

Missing No difficulty; the Can estimate data Great loss in
data experiment is but some loss efficiency if several
reduced to unequal efficiency values are missing
replications

Completely Randomized Design

1. The treatment is assigned completely at random so that each experimental
unit has the same chance of receiving any one treatment.
a. Determine the total number of experimental plots (n) as the
product of the number of treatments and the number of
replication (t).
b. Assign plot numbers to each experimental plot in any
convenient manner; for example, consecutively from1 to n.
c. Assign the treatments to the experimental plots by
randomization:

Prepare identical pieces of paper and divide them into t groups, each
group with r pieces of paper. Label each piece of paper of the same group with
the same letter (number) corresponding to a treatment. Uniformly fold each of
the n labeled pieces of paper, mix them thoroughly and place in a container.
For example there should be 20 pieces of paper (t=4) and r=5) five each with
treatments A, B, C, D appearing on them. Draw one piece of paper at a time,
without replacement and with constant shaking of the container after each
draw mix it again. Assign the treatments to plots based on the corresponding
treatment label and sequence drawn.

2. Any difference among experimental units receiving the same treatment is
considered as experimental error. In other words
CRD is applicable only for experiments having homogeneous
experimental units (e.g. laboratory experiments where environmental effects
are relatively easy to control)