Unit 3

Question 1

population

Answer 1

the entire group we want information about

Question 2

sample

Answer 2

a part of the population we actually examine to gather information about the population

Question 3

census

Answer 3

collects data from every individual in the population

Question 4

observational study

Answer 4

observes individuals and measures variable of interest but does not attempt to influence the responses

Question 5

retrospective

Answer 5

examine data for a sample of individuals

Question 6

prospective

Answer 6

follow a sample of individuals into the future collecting data

Question 7

sample survey

Answer 7

type of observational study that collects data from a sample in an attempt to learn about the population from which the sample was taken

Question 8

experiment

Answer 8

deliberately imposes some treatment on individuals to measure their responses

Question 9

convenience sampling

Answer 9

uses subjects that are readily available

Question 10

advantage of convenience sampling

Answer 10

easy and less costly to collect

Question 11

disadvantage of convenience sampling

Answer 11

not representative of the population

Question 12

voluntary response sample

Answer 12

a sample obtained by allowing subjects to decide whether or not to respond

Question 13

advantage of voluntary response sample

Answer 13

easy to collect

Question 14

disadvantage of voluntary response sample

Answer 14

over represents people with strong opinions

Question 15

simple random sample

Answer 15

n individuals from a population are chosen in a way that every set of n individuals has an equal chance of being selected to be in the sample

Question 16

advantages of simple random sampling

Answer 16

easy to accomplish using a table of random digits; likely to produce samples that are good representatives of the population

Question 17

disadvantages of simple random sampling

Answer 17

none of

Question 18

stratified random sampling

Answer 18

divide the population into groups of similar individuals (strata) then select an SRS within each strata & combine them to form your sample

Question 19

advantage of stratified random sampling

Answer 19

can produce more exact information in large populations by taking advantage of the fact that individuals in the same strata are similar to one another

Question 20

disadvantage of stratified random sampling

Answer 20

not appropriate unless strata are easily defined

Question 21

cluster sampling

Answer 21

divide the population into clusters then randomly choose a few clusters to become part of your sample

Question 22

advantage of cluster sampling

Answer 22

don’t need a list of entire population

Question 23

disadvantage of cluster sampling

Answer 23

more variability between samples depending on how clusters are determined

Question 24

systematic random sampling

Answer 24

randomly select an arbitrary starting point & then select every kth member of the population

Question 25

advantage of systematic random sampling

Answer 25

every member has an equal probability of being selected

Question 26

disadvantage of simple random sampling

Answer 26

not every sample of size n has an equal chance of being selected