Question

The changing climate will probably bring more rain to California, but we don't know whether the additional rain will come during the winter season or extend into the long dry season in spring and summer. Kenwyn Suttle of the University of California at Berkeley and his coworkers wanted to compare the effects of three treatments: added water equal to 20% of annual rainfall either during January to March (winter) or during April to June (spring), and no added water (control). Eighteen plots of open grassland, each with area 70 square meters, were available for this study. One response variable was total plant biomass, in grams per square meter, produced in a plot over a year. Describe a completely randomized design for this experiment. Write a few sentences describing how you would implement your design.

Answer 1

Number each of the treatments 1 — 3 and place them into a hat.

Explanation:

Number each of the treatment I — 3 and place them into a hat. Shake the hat vigorously to mix the lumbers. Then for each plot of land, draw out a umber. The number drawn out from the hat will represent the treatment that will be imposed on the plot.

The number drawn out of the hat will be replaced and another number will be drawn for the next plot of land. Then, at the end of the experiment, the plant biomass of each plot will be measured and an average will be taken for all three treatments to determine which treatment had the greatest effect on plant biomass.