Chapter One

Question 1

Variable

Answer 1

Any characteristic recorded for a case
Ex: age, gender

Question 2

Case

Answer 2

Objects we obtain information about

Question 3

Categorical Variable

Answer 3

Divides cases into groups. Each case fits into exactly one out of 2+ categories

Question 4

Quantitative Variables

Answer 4

Measures/ records a numerical quantity for each case. Quantitative

Question 5

Population

Answer 5

All individuals or objects of interest

Question 6

Sample

Answer 6

Subset of the population (denoted by n)

Question 7

Sampling bias

Answer 7

The method of selecting a sample causes the sample to differ from the population

Question 8

Simple random sample

Answer 8

Each unit of the population has the same chance of being selected

Question 9

Sampling/ selection bias

Answer 9

Participants aren’t representative of the population

Question 10

Non response bias

Answer 10

Participants included don’t participate

Question 11

Response bias

Answer 11

Participants who respond are motivated/ pressured to respond in ways that don’t represent their true feelings

Question 12

Question wording

Answer 12

The way questions are phrased influences the way participants respond

Question 13

Inaccurate responses

Answer 13

Forms of bias lead participants to picking answers that don’t represent their true feelings

Question 14

Association

Answer 14

Values of one variable tend to be related to the values of the other variable

Question 15

Causation

Answer 15

Changing the value of one variable influences the value of the other variable

Question 16

Confounding variable

Answer 16

3rd variable associated with both explanatory and response variable. Can offer a plausible explanation or complication between 2 variables of interest

Question 17

Observational study

Answer 17

Researcher doesn’t actively control the value of any variable but observes values

Question 18

Randomized experiment

Answer 18

The value of the explanatory variable for each unit is determined randomly, before the response is measured.

Question 19

Determining causality

Answer 19

Can only be done through a randomized experiment, since it evens out the influence of a confounding variable

Question 20

Randomized comparative experiment

Answer 20

Randomly assign cases to different treatment groups and compare results on the response variables

Question 21

Matched pairs experiment

Answer 21

Each case gets both treatment in random order, or cases get paired up. Allows us to examine individual differences in the response variable between the two treatments

Question 22

Control group

Answer 22

Allows for comparison to see if there’s a difference from before the experiment to after

Question 23

Placebo effect

Answer 23

People experience the effect they think they should be experiencing, even if they aren’t receiving treatment

Question 24

Single blind experiment

Answer 24

Participants don’t know if they’re being given a real o placebo treatment

Question 25

Double blind experiment

Answer 25

Neither participants or researchers know who gets real or placebo treatment

Question 26

Methods of matching

Answer 26

Each case gets both treatment Cases matched with another case with similar characteristics Family relationships (couples, twins, siblings)