Sound experimental design is of vital importance when conducting any scientific experiment. Choices made at the design stage have the potential to drastically impact the results of any study. A strong experimental design gives the researcher an improved chance of a successful experiment. A poorly considered or implemented design can have a ruinous effect on the investigation. In this short course basic elements of experimental design such as randomization, replication, and blocking will be discussed using real world experiments. Interpretation of experimental results will be compared and contrasted with interpretation of results from observational studies.
Before you show up:
Please complete this short course question prior to coming to the course. An image can be found in the attached file.
A grape researcher is interested in testing the effect of 4 pesticides on the disease rate on his grapes. For his experiment he has 16 total vines arranged in four plots. Each vine has a trunk at the center and two cordons extending from the trunk. Many grape clusters grow on each cordon.
To administer the pesticides, the farmer randomly assigns one pesticide (labeled A, B, C, and D) to each of the plots. He then sprays the assigned pesticide on all four vines in each plot, walking from north to south in each case.
With 16 vines, 32 cordons, and a great number of grape clusters per cordon, how many experimental replicates does the farmer have for each pesticide?