Question

A professor sent his graduate student to the green house to apply treatments to potted plants.  There were 4 treatments and a total of 12 pots containing plants.  The professor told the student to “randomly assign pots to treatments.”  The pots were arranged on a table with 4 rows each containing 3 plants.   The graduate student put 4 tickets in a hat, one each with the numbers 1, 2, 3, and 4 written on them.   As he got to each row, he drew a ticket out of the hat and applied the treatment corresponding to that number to all 3 pots in that row.  a)  What is the experimental unit for the student’s design?  b)  What did the professor intend to be the experimental unit?  c)  True or False and Explain.  The design implemented by the student has no true replication of any treatment group and so the AOV for a one‐ way design that we have studied in this class does not apply.   

Answer 1

Experimental unit is the smallest division of the experimental material to which we apply the treatments and on which we make observation on the variable under study

After the treatments and the experimental units are decided the treatments are alloted to experimental units at random to avoid any type of bias

In this experiment,the students were to apply" treatments to potted plants".But the professor told randomly assign" pots to treatments"

a)the experimental unit for the students design is the potted plants

b)the professor intend "treatments" to be the experimental unit

c)true,the randomisation technique applied by the student is not at all significant for one way design.

The students separates the experimental units and apply same treatments all over in a single row.This is not the procedure of randomisation use in completly randomised design.Treatments are randomly allocated to each experimental units