What is Stats?
What is the definition of statistics?
Statistics is a way of reasoning, along with a collection of tools and methods, designed to help us understand the world.
What are the 5 W’s?
Who, What, Where, When, Why
What are the 2 types of variables?
Categorical and Quantitative
For this chapter, we discussed data displays for which type of variable?
Categorical
What is the definition of data?
Data is any collection of numbers, characters, images, or other items that provide information about something.
Apart from the 5 W’s, what is commonly asked as well?
How
What is a Quantitative variable?
A measured variable that answers questions about the quantity of what is being measured. Units are included.
What were the three main data displays we discussed?
Bar charts, pie charts, and contingency tables
Why is it important to include context with data?
Without context, we don’t know what we are looking at. Data becomes useless.
What does the WHO tell us?
Individual cases form which we collected data from.
True or False: Categorical variables can not be represented with numbers.
FALSE! Categorical variables can also be represented using numbers.
What is the area principle?
Data needs to be accurately represented in accordance to their value in a display.
Where have you seen statistics being used in the real world?
Answers may vary but can include polls, elections, COVID cases, new student surveys
What does the WHEN tell us?
When the data was collected/ when the study took place.
Identify the variable and determine whether it is categorical or quantitative.
A medical researcher measures the increase in heart rate of patients under a stress test.
Variable: Heart rate
Quantitative
What does it mean for variables to be independent?
There is no association between the variables. They do not affect one another.
True or False: Data can only be represented by numbers.
FALSE!
Data can be numbers, labels, record names, etc.
Identify the 5 W’s and How of the following excerpt.
Pew Charitable Trusts conducted a longitudinal study that has followed families from 1968 to the present to gain a better understanding of the American Dream and economic mobility. They surveyed 2227 American families asking, “What is your “Family income” including all taxable income (such as earnings, interest, and dividends) and cash transfers (such as Social Security and welfare) of all family members?”
Who: American families (subjects)
What: Family income
Why: To understand the relationship between the American Dream and economic mobility.
Where: United States of America
When: 1968 to present
How: Longitudinal study
Identify the variable and determine whether it is categorical or quantitative.
A listing posted by the Arby’s restaurant chain gives, for each of the sandwiches it sells, the type of meat in the sandwich, the number of calories, and the serving size in ounces. The data might be used to assess the nutritional value of the different sandwiches.
Categorical: Type of meat
Quantitative: Number of calories, Serving size
What is the difference between conditional distribution and marginal distribution?
Marginal distribution are the totals on a contingency table where the conditional distribution shows the distribution of one variable given a condition of the other.