Assume that you have a small garden and are interested in knowing whether particular species of tomato plants will yield more tomatoes. You are also interested in knowing if adding fertilizer will increase the growth of tomatoes. You will try three species of tomatoes with and without fertilizer and measure the total weight of the tomatoes produced. Because of limited space, your garden is broken into three small plots in separate locations. Each plot has the same total area ( each plot is big enough to grow 12 plants), but the three plots have differing amounts of sunlight. Write a brief outline for an experimental design.
a. Identify any extraneous variables that may potentially bias your results. How will these potential biases be addressed?
b. List each factor in the study and determine whether it is fixed or random. Also note whether it is crossed with or nested within other factors.
c. Specify the units and sample size for this study.
d. List each factor- level combination and describe how you will use randomization in this study.
e. List the factors and the corresponding degrees of freedom that will occur in the ANOVA table.
f. Will this be a completely randomized, block, or split- plot design? Explain.