Chapter 1 Stats Starts Here

Stats Starts Here Statistics gets no respect, and Statistics courses are not necessarily chosen as fun electives, but Statistics can be fun! Learning to think clearly with data will open your eyes to seeing the world more clearly…

What Is (Are?) Statistics? Statistics (the discipline) is a way of reasoning, along with collection of tools and methods, designed to help us understand the world. Statistics (plural) are calculations made from data. Data are values with a context.

What are some examples of how data is used in the world? Facebook ads on your page? Grocery store coupons? In this class, you will learn to design experiments to figure out how to make conclusions from data.

Just for fun: Summarize each discipline in a few words -Economics: Money -Biology: Life -Psychology: Why we think what we think -Anthropology: Who? -Engineering: how? -Statistics: Variation

What is Statistics Really About? Statistics is about variation. Statistics helps us make sense of the world by seeing past the variation to find patterns and relationships. All measurements are imperfect, since there is variation that we cannot see. Statistics helps us to understand the real, imperfect world in which we live.

In Summary Statistics can be (and is) fun! Statistics gives us a way to work with the variability in the world around us. We are embarking on an exciting journey of learning Statistics…

Classwork: Read Time magazine “America: By the Numbers.” Write a 1-page reflection answering the following questions. Use textual evidence to support your claim. Why is finding the “Average American” such a challenge?  Why can using averages to define Americans be so problematic? How do you compare to the examples of the “Average American” that are given in this article? Statistics is all about variation. How does this article show that? Do you want to be the “Average American”? Explain why or why not.

Video: Shift happens https://www.youtube.com/watch?v=uqZiIO0YI7Y&t=44s Discussion topic: What are your thoughts on this video? What did you find interesting or surprising?

Classwork M&M’s activity

What Are Data? A collection of numbers, characters, images, or other items that provide information. Not all data represented by numbers are numerical data Can you think of an Example? example: Conduct grades 1=excellent, 2=good, 3=fair, 4 = poor). Data are useless without their context…

The “5 W’s and H” To provide context we need the 5 W’s and H: Who What (and in what units) When Where Why (if possible) and How of the data.

Who The Who of the data tells us the individual cases for which (or whom) we have collected data. Individuals who answer a survey are called respondents. People on whom we experiment are called subjects or participants. Animals, plants, and inanimate subjects are called experimental units.

What and Why Variables are characteristics recorded about each individual. The variables should have a name that identify What has been measured.

What and Why (cont.) Some variables have units that tell how each value has been measured and tell the scale of the measurement.

What and Why (cont.) A categorical (or qualitative) variable names categories and answers questions about how cases fall into those categories. Categorical examples: sex, race, ethnicity A quantitative variable is a measured variable (with units) that answers questions about the quantity of what is being measured. Quantitative examples: income ($), height (inches), weight (pounds)

Identifying Identifiers Identifier variables are categorical variables with exactly one individual in each category. Examples: Social Security Number, ISBN, FedEx Tracking Number Don’t be tempted to analyze identifier variables.

Where, When, and How When and Where give us some nice information about the context. Example: Values recorded at a large public university may mean something different than similar values recorded at a small private college.

Where, When, and How (cont.) How the data are collected can make the difference between insight and nonsense. Example: results from Internet surveys are often useless

Think, Show, Tell There are three simple steps to doing Statistics right: first. Know where you’re headed and why. is about the mechanics of calculating statistics and making graphical displays. what you’ve learned. You must explain your results so that someone else can understand your conclusions.

What Can Go Wrong? Don’t label a variable as categorical or quantitative without thinking about the question you want to answer. Just because your variable’s values are numbers, don’t assume that it’s quantitative.

What have we learned? Data are information in a context. The 5 W’s and H help with context. You must have context to say anything useful about the data.

What have we learned? (cont.) We treat variables as categorical or quantitative. Categorical variables identify a category for each case. Quantitative variables record measurements or amounts of something and must have units.

Homework: Chapter 1 Homework: Stats Starts Here Chapter 1 Quiz on _______________________