Question

Short answer

A. What are two tests that are used to check for equal variance in two samples?

B. Why can we not simply use multiple t-tests to determine if there is a difference between treatments if we have an experiment with many treatments?

C. What are the two graphical methods to detect deviations from normality, and how do they work (one sentence description of each)?

D. When would you use an a priori or an a posteriori tests? Give one example of each

Answer 1

A. What are two tests that are used to check for equal variance in two samples?

F-test and Welch's t-test.

B. Why can we not simply use multiple t-tests to determine if there is a difference between treatments if we have an experiment with many treatments?

Type I errors will be addictive.

C. What are the two graphical methods to detect deviations from normality, and how do they work (one sentence description of each)?

Histogram: A histogram is a graphical display of data using bars of different heights.

Normal probability plot: The normal probability plot is a graphical technique for assessing whether or not a data set is approximately normally distributed.

D. When would you use an a priori or an a posteriori tests? Give one example of each

A posteriori knowledge is empirical, experience-based knowledge, whereas a priori knowledge is a non-empirical knowledge. Standard examples of a posteriori truths are the truths of ordinary perceptual experience and the natural sciences; standard examples of a priori truths are the truths of logic and mathematics.