It’s a Dangerous World Out TherePitfalls and Perils • People often use statistics to attempt to persuade you to their point of view. • Purchase? • Support? • Action?
Bias • One of the most common misuses of statistics • Definition: Biased Sample • A sample that does not represent the intended population and can lead to distorted findings. • Can be intentional or unintentional
Example: National Golf Day Sampling Bias • Hand out survey form only at golf courses • Design the survey: We would like to propose a national golf holiday, on which everybody gets the day off from work and plays golf all day. (This means you miss school or work, and don’t need permission from anyone.) Are you in favor of this proposal? A) Yes, most definitely B) Sure, why not? C) No, I would rather spend the entire day at school or work. Question Wording
So, we’ve talked about…. • Sampling bias • Question wording
Deceptive Graphs and Charts Sodas Consumed • Ask yourself: • Sodas per capita in the US? • Thousands of gallons of soda? • Millions of cans?
Deceptive Graphs and Charts • Better…. Sodas Consumed USA, Calendar Year (in millions of gallons)
Self-selected surveys • Internet polls: You choose whether or not to participate • Television “phone-in” (WBKO) • Strong feelings, for or against • Missing anyone?
So, we’ve talked about…. • Sampling bias • Question wording • Deceptive graphs • Self-selected surveys
The LEAST You Need to Know… 1 Statistics is a vital tool that provides organizations with the necessary information to make good decisions.
The LEAST You Need to Know… 2 The field of statistics evolved from the early work of European mathematicians during the 17th century.
The LEAST You Need to Know… 3 Descriptive statistics focuses on the summary or display of data so we can quickly obtain an overview.
The LEAST You Need to Know… 4 Inferential statistics allows us to make claims or conclusions about a population based on a sample of data from that population.
The LEAST You Need to Know… 5 We are all consumers of statistics and need to be aware of the potential misuses that can occur in this field.