Populations, Samples, Variables

Question 1

population

Answer 1

collection of things having some quantifiable characteristic in common

Question 2

inclusion criteria

Answer 2

common characteristics of a population (what they HAVE to have)

Question 3

exclusion criteria

Answer 3

common characteristic members of a population lack (what they CAN’T have)

Question 4

internal validity

Answer 4

the study was done right

Question 5

external validity

Answer 5

the study means something

Question 6

sample

Answer 6

a group of individuals that represents the population

Question 7

random sampling

Answer 7

every member of the population has an equal chance at being selected

Question 8

Law of Independence

Answer 8

selection of one member does not influence the chance of choosing any other

Question 9

parameter

Answer 9

a true numerical value the summarizes the data; stable but not constant

Question 10

statistic

Answer 10

estimate of a parameter in a sample

Question 11

confidence interval

Answer 11

statistic +/- margin of error

Question 12

Relationship between Sample Size and CI?

Answer 12

Larger sample size = narrower CI

Question 13

3 Descriptions of Variables

Answer 13

1. Type
2. Scale of Measurement
3. Distribution of Values

Question 14

3 Types of Variables

Answer 14

1. Qualitative
2. Quantitative
3. Categorical

Question 15

5 Scales of Measurement

Answer 15

1. Binary
2. Nominal
3. Ordinal
4. Interval
5. Ratio

Question 16

The Two Main Categories of Distribution Patterns

Answer 16

1. Normal/Gaussian (parametric)
2. Nonparametric

Question 17

Quantitative Variable

Answer 17

numbers that reflect a value
can be discrete (1 through 5) or continuous (wide range)

Question 18

Categorical Variable

Answer 18

no numerical value EVEN IF categories have been assigned a number

Question 19

3 Scales within Categorical Variables

Answer 19

1. Binary/dichotomous (yes/no, present/absent)
2. Multinomial/nominal (coat color, eye color)
3. Ordinal (small/medium/large)

Question 20

distribution

Answer 20

pattern seen when you graph the frequency of the variable’s different values

Question 21

Normal Distribution

Answer 21

pretty lil bell curve, describe with mean and standard deviation (95% of observations fall within 2 standard deviations of the mean)

Question 22

How to describe nonparametric distributions?

Answer 22

median and percentiles

Question 23

p-value

Answer 23

used to determine if a change we observed is real or if it just happened by chance