Intro to Statistics
The type of statistical method that will be used to analyze data will depend on the experimental design, therefore the specific questions that the experiment is intended to answer must be clearly identified before carrying out the experiment. An attempt should also be made to identify known or expected sources of variability in the experimental units because one of the main aims of a designed experiment is to reduce the effect of these sources of variability on the answers to questions of interest.
Experiments are designed in order to improve the precision of our answers. There are different types of experimental designs because of different questions desired to be answered.
Experimental design is the process of planning a study to meet specified objectives. Planning an experiment properly is very important in order to ensure that the right type of data and a sufficient sample size and power are available to answer the research questions of interest as clearly and efficiently as possible. Because the validity of an experiment is directly affected by its construction and execution, attention to experimental design is extremely important.
In the next four main sessions, we will explore the main components or factors of an experimental design, the major categories of experimental designs ( i.e randomized complete block designs, factorial experiments and split plot designs), what an experimental design actually test for, selection of a statistical method used to analyze data of a specific design, the limitations and assumptions associated with each analytical method, and interpreting the results of a statistical analysis.