Make it an experiment! In the following observational studies, describe changes that could be made to the data collection process that would result in an experiment rather than an observational study. Also, offer suggestions about unseen biases or lurking variables that may be present in the studies as they are described here.
(a) A friend of yours likes to play Texas hold 'em. Every time that he tells you about his playing, he says that he won.
(b) In an introductory statistics class you notice that the students who sit in the first two rows of seats had a higher score on the first exam than the other students in the class.