Ch. 1 : Explore/Understand Data and Graphs

Question 1

What is population?

Answer 1

the collection of ALL data values (usually large, unknown, and impossible to obtain all values)

Question 2

What is a sample?

Answer 2

a subset of the population and we can measure characteristics

Question 3

What is a sample size?

Answer 3

number of observations in a sample (n)

Question 4

Observational units

Answer 4

are ROWS: individual cases about whom (or which) we record some characteristics

Question 5

Variables

Answer 5

are columns: characteristics of a person or thing that can be assigned a number or a category

Question 6

Types of Variables

Answer 6

Categorical and Numerical variables

Question 7

Categorical Variable

Answer 7

aka Qualitative/ names categories and answers questions about how cases fall into these categories. Data values are usually words

Question 8

Numerical Variable

Answer 8

aka Quantitative/ a measured variable with units that answers questions about the quantity of what is measured. Data Values are numbers

Question 9

What are frequencies?

Answer 9

(or counts) are a natural way to summarize categorical variables

Question 10

What are Two-Way Tables?

Answer 10

Tables displays the counts of two categorical variables at a time conditional on each other

Question 11

What does it mean to establish Causality?

Answer 11

means to show that an outcome is effected by some treatment

Question 12

Treatment Group?

Answer 12

those who receive the treatment in an experiment

Question 13

Control Group

Answer 13

those who did NOT receive the treatment in an experiment

Question 14

What does it mean if two things are Associated?

Answer 14

when an outcome occurs more often with one group than the other (treatment and outcome are _)

Question 15

What is a confounding variable?

Answer 15

a characteristic other than the treatment that causes both outcomes

Question 16

Observational Study?

Answer 16

Researchers DON’T assign choices; they simply see them/ “see and study”
-they do not demonstrate a causal relationship

Question 17

Experiment?

Answer 17

the researcher actively and deliberately manipulates the treatment variable and assigns the subjects to those treatments, generally at random (one treatment variable manipulated and one outcome variable to measure)
-possible to demonstrate a causall relationship

Question 18

Principles of Experimental Design

Answer 18

Large Sample Size, Controlled and Randomized, Double-Blind, Placebo

Question 19

Random assignment

Answer 19

helps balance bias (which happens when assignments aren’t r_m and results are influenced in certain direction