definitions for module 1

Question 1

What is a census?

Answer 1

a sample that includes everyone and samples the entire population

Question 2

What are inferences?

Answer 2

when researches made educated guesses based on data from samples

Question 3

what are samples?

Answer 3

a subset of the population

Question 4

what are the two types of inferences?

Answer 4

population inferences and causal inferences

Question 5

what is a population inference?

Answer 5

results that are generalized to the entire population

Question 6

what are causal inferences?

Answer 6

the difference in response caused by the difference in treatments of the groups

Question 7

what is something that is required when making a population inference?

Answer 7

there needs to be random sampling to eliminate bias

Question 8

what is simple random sampling (srs)?

Answer 8

randomly selecting people, everyone has the same chance of getting selected

Question 9

what is stratified random sampling?

Answer 9

the population is divided into groups called strata and people are chosen at random from each group

Question 10

what is systemic random sampling?

Answer 10

start from a randomly selected subject, then select every kth person

Question 11

what is cluster random sampling?

Answer 11

splitting the population into similar clusters and selected one or a few to preform a census

Question 12

What are the different sources of bias?

Answer 12

Selection bias, response bias, voluntary response bias and nonresponse bias

Question 13

what is selection bias?

Answer 13

(underrepresentation), when a portion of the population is not sampled at all/not enough

Question 14

what is response bias?

Answer 14

anything in the survey design that influences the response

Question 15

what is voluntary response bias?

Answer 15

when people can chose if they want to participate or not

Question 16

what is nonresponse bias?

Answer 16

when a large proportion fail to respond to the survey

Question 17

What is observational study?

Answer 17

observing individuals and measures variables of interest but does not influence the response

Question 18

what is a retrospective study?

Answer 18

looking at history and past data

Question 19

what is a prospective study

Answer 19

collecting data as the events unfold

Question 20

what is a parameter?

Answer 20

numerical summaries that describes a characteristic of the population

Question 21

what is a statistic?

Answer 21

numerical summary of the characteristic of the sample

Question 22

What is the symbol of mean (statistic)

Answer 22

ȳ

Question 23

what is the symbol of mean (parameter)

Answer 23

µ

Question 24

what is the symbol for standard deviation (statistic)

Answer 24

s

Question 25

what is the symbol for standard deviation (parameter)

Answer 25

σ

Question 26

what is the symbol for correlation (statistics)

Answer 26

r

Question 27

what is the symbol for correlation (parameter)

Answer 27

ρ

Question 28

what is the symbol for regression coefficient (statistic)

Answer 28

b

Question 29

what is the symbol for regression coefficient (parameter)

Answer 29

β

Question 30

what is the symbol for proportion (statistic)

Answer 30

p̂

Question 31

what is the symbol for proportion (parameter)

Answer 31

p

Question 32

What are details that we need to have when recording data?

Answer 32

who, what, when, where, why and how

Question 33

What is the WHO in data?

Answer 33

subjects/participants (in a sample), respondents (survey), experimental units (inanimate)

Question 34

What is the WHAT in Data?

Answer 34

characteristics/variables

Question 35

what is the WHY in data?

Answer 35

why are we studying this? what is the purpose of this experiment?

Question 36

what is the WHERE and WHEN in data?

Answer 36

not necessary but gives us additional context and relevance in a study

Question 37

what is the HOW in data?

Answer 37

how is the data being collected? will it be biased?

Question 38

what are categorical/qualitative variables?

Answer 38

variables that place subjects into certain groups

Question 39

What is nominal in a categorical variable?

Answer 39

categories have no order

Question 40

what is ordinal in categorical variables?

Answer 40

the levels have some order

Question 41

what are numerical/quantitative variables?

Answer 41

variables that measure the numerical quantity in each subject

Question 42

what are discrete numerical variables?

Answer 42

can only take on distinctive values | ex: how many siblings do you have, must be a whole number, you cannot have 1.45 siblings

Question 43

what is a continuous numerical variable?

Answer 43

can take on any variable in a given interval ex: how long does it take you to eat breakfast? Anywhere between 0-25 minutes, including decimals

Question 44

what is an identifier variable?

Answer 44

a variable used to determine an identity, ie. student ID