Causal and Statistical Reasoning - Open and Free

Causal and Statistical Reasoning - Open and Free: "Once upon a time in Pearson Land, there was a young man named Harry who was nearly always late. Try as he might, Harry could not seem to get to any of his appointments on time. At the university, Harry took a course on research methods in social science, which, fortunately for him, had a professor who showed up late a lot too. In this class Harry learned the virtues of gathering hard data as opposed to soft opinions, and he became so enamored of the scientific method that he decided to apply it to himself. 'I will study the habits of people who are early and who are late,' Harry proclaimed, 'and let science guide me to the land of the punctual.'

Harry carefully studied dozens of people for several weeks, recording lots information about them. He analyzed his data and discovered that one property was strongly associated with being late -- hurrying! People who hurried vigorously on the way to their appointments were almost always late. People who walked at a normal pace were almost always on time! This must be right, Harry thought, I'm always hurrying and I'm always late too. Thanks to Science, I have finally found the answer -- I must stop hurrying to get to my appointments, and stroll in a leisurely manner instead!"