M5x


Focus Questions for Chapter 5


1.	What is bias?


2.	What is variability?


3.	What is meant by a placebo, and what is its purpose?


4.	What is the difference between the population and the sample in a 
        survey or experiment?


5.	What is meant by a randomly selected sample of n people from a 
        population?


6.	Describe the two kinds of blindness commonly used in an experiment 
        which will be statistically analyzed.


7.	Describe the typical uses and effects of randomness in a survey or 
        experiment.


8.	Discuss whether and how the following affect bias and/or variability:

	a)      blindness (single or double)

	b)	randomness

	c)	sample size


9.	What is confounding?  Give an example.