unit 3

Question 1

population vs sample

Answer 1

population is the group being studied, sample is subset of population

Question 2

observational study

Answer 2

no treatment, data is observed and recorded without manipulating variables.

Question 3

experiment

Answer 3

study where variable/s are manipulated to observe the effect.

Question 4

inferences made from…

Answer 4

observational studies

Question 5

SRS (simple random sample)

Answer 5

each individual has the same chance of being chosen

Question 6

Stratified random sampling

Answer 6

divides group based on characteristic, data is taken from each stratum

Question 7

cluster sampling

Answer 7

divides population into groups, data is collected from each cluster

Question 8

systematic sampling

Answer 8

selecting an individual after a certain number of them from a random start point

Question 9

stratified sampling advantage vs disadvantage

Answer 9

all groups are represented, more complex to organize

Question 10

cluster sampling advantage vs disadvantage

Answer 10

cost-effective, less precise

Question 11

systematic sampling advantage vs disadvantages

Answer 11

simple to implement, can be bias in hidden pattern chosen

Question 12

voluntary response sampling

Answer 12

people choose to participate in study, bias

Question 13

convenience sampling

Answer 13

choosing people easiest to reach

Question 14

how does undercoverage lead to bias

Answer 14

groups are left out of sampling (underrepresentation)

Question 15

nonresponse bias

Answer 15

individuals choose not to respond

Question 16

confounding

Answer 16

effects of variables are mixed, so you cant determine which one is actually causing an effect.

Question 17

experimental units

Answer 17

subjects being studied/receive treatment

Question 18

blinding prevents

Answer 18

bias

Question 19

random assign. is important bc

Answer 19

ensure groups are comparable and valid responses are given `

Question 19

controlling the variables helps

Answer 19

eliminate influence on results

Question 19

randomized block design

Answer 19

experimental units are divided into groups based on characteristic, treatments are randomly assigned within blocks.

Question 19

matched pairs design

Answer 19

pairs similar units together and assigns different treatment to each person in the pair

Question 20

statistically significant

Answer 20

observed results are unlikely due by chance, treatment has effect

Question 21

inferences about a population made when

Answer 21

sample is representative

Question 22

cause and effect inferences made when

Answer 22

there is random assignment and control of variables