Lecture 2 - Choosing a sample

Question 1

Simple Random Sample (SRS)

Answer 1

Randomly selecting people.

Question 2

Stratified sample

Answer 2

Break your population up into groups (by state, gender, income, etc) (note that this is the same as cluster sample). Then choose some people from all groups.

Question 3

Cluster sample

Answer 3

Break your population up into groups (by state, gender, income, etc) (note that this is the same as stratified sample). Then choose all people from some groups.

Question 4

Convenience sample

Answer 4

Choose people in a way that’s convenient for you (bad!). For example, talking only to your friends.

Question 5

Numerical variable

Answer 5

Variable that is best represented by a number.

Question 6

Continuous numerical variable

Answer 6

Numerical variable that can take on any value in a range (e.g. height, weight, score in a class)

Question 7

Discrete numerical variable

Answer 7

Numerical variable that can take on only specific values (e.g. zip code, number of siblings you have, etc).

Question 8

Categorical variable

Answer 8

Variable that is best represented by something other than a number (e.g. gender, ethnicity, etc).