Principle of experimental design

1. Replication

• Refers to repeated application of treatment.
• Has following function:

i) Provide estimate of experimental error for test of significance.

ii) Improve precision of experiment.

• Following factors determine the number of replications

a) Uniformity of experimental units

b) Experimental designs

c) Degree of precision required

d) No. of treatment

e) Time allotment

f) Budget availability

2. Randomization

• When all the treatment have equal chance of being allocated to different experimental units, it is called randomization.
• It has following functions:

i) Remove bias and extraneous variation which aren’t controllable

ii) Form bias for any statistical test.

3. Local control : Grouping of homogenous experimental units.