This document discusses key aspects of research design including replication, randomization, and blocking. It explains that replication involves repeating experiments to test if units respond the same way to treatments, allowing significance to be tested. Randomization ensures unbiased estimates by randomly assigning experimental units to treatments. Blocking balances groups and controls for extraneous variables through homogeneous blocking. The document provides an example experimental design layout.

1. Research Design

3. Replication Repetition of the basic experiment See if units respond the same way to the same treatment Significance of the results can be tested Number of replicates depends on Degree of precision required Degree of homogeneity of the sample Number of treatments in the study

4. Randomization Chance assignment of experimental units to the treatment or vice-versa Assures valid and unbiased estimates of means and differences between treatments Test for significance is valid

5. Local control Balancing grouping and blocking of experimental units in the experimental design Blocking – assignment of units to a block to ensure that the block is homogeneous

8. 5 12 8 14 15 4 10 11 2 3 9 13 1 7 6 Control 1% 5% 10% + Control 8 9 13 1 5 12 3 11 2 8 6 14 4 7 10

10. Block Experimental Subjects A B C 1 2 3 7 6 8 11 12 13 4 5 9 10 14 15 Control 1% 5% 10% + Control 1 4 2 3 5 9 8 7 6 10 14 15 13 12 11

11. Group Exercise Identify dependent, independent, and extraneous variables. Enumerate the treatments given. How many replicates were used? How many samples were used in the project? How were these chosen from the population? Which type of research design (CRD or RCBD) was chosen or was most appropriate for the project. Why? Bonus: What was the test of significance used?

12. Group Exercise Groups 1 and 2 – Comparative analysis of the effects of VCO and olive oil on the cholesterol levels in rabbits Groups 3 and 4 – Utilization of blood of stray dogs as a component of blood agar plates Groups 5 and 6 – Formulation of an all-organic nutrient solution for lettuce Groups 7 and 8 – Mango seed kernels as an alternative source of starch in flour Groups 9 and 10 – Lecithin organogels as a topical aid of green tea extracts for the treatment of inflammatory skin disease