Question

A forest products company wishes to do an experiment in a clear-cut white spruce
forest to determine the effect of three levels of a fertilizer treatment (3-20-3 N,P,K) on white
spruce seedlings to see if they can accelerate re-establishment of a white spruce stand. The
fertilizer levels are 2 kg, 5 kg, and 10 kg of 3-20-3 fertilizer/ha. Two years after treatment,
heights of treated seedlings in the clear-cut area are measured.

a) What is the treatment factor here? What is the response variable?
b) What kind of experimental design might be appropriate to test for a treatment effect of
fertilizer level? Explain and defend your choice.
c) What precautions would the forest company need to take to ensure unbiased estimates of
treatment effects in this experiment?

Answer 1

a. The treatment factor is fertilizer levels and the response variable is the heights of treated seedlings in the clear-cut area.

b. The experimental design that might be appropriate to test for a treatment effect of fertilizer level is one-way ANOVA design because there is one factor with three levels and one response variable and the objective is to determine the effect of these levels on the response.

c. The precautions to ensure the unbiased estimates of treatment effects would be:

1. Ensure that an appropriate sampling technique is used.

2. The data collection process is free from measurement errors.

3. Avoiding data that comes under the unrepresentativeness of the population.

Good luck with your studies!!!

Good luck with your studies!!!