Basic Statistics II (4) - End E1

Question 1

What are measures of central tendency?

Answer 1

describe the typical or central value in a distribution
- mean, median, mode

Question 2

What are measures of dispersion?

Answer 2

describe the spread of data
- range, standard deviation, variance

Question 3

What is standard deviation?

Answer 3

measures the amount of variation or dispersion from the average

Question 4

What does a high standard deviation mean?

Answer 4

indicates that the data points are spread out over a large range of values

Question 5

What does a low standard deviation mean?

Answer 5

the data points tend to be very close to the mean (also called expected value)

Question 6

What is variance?

Answer 6

directly related to standard deviation

the square of it - sigma squared

Question 7

Would this have a high or low variance?

Answer 7

low

Question 8

What is categorical data?

Answer 8

nominal
ordinal

Question 9

What is numerical data?

Answer 9

interval
ratio

Question 10

What is nominal data?

Answer 10

refers to categorically discrete data such as name

part of categorical data

Question 11

What is ordinal data?

Answer 11

data that has a discrete ranking

ex. freshman, sophomore, etc

order like ordinal

type of categorical data

Question 12

What is interval data?

Answer 12

numerical data that is measured along a scale
each point is at equal distance from one another

type of numerical data

Question 13

T/F: Intervals can have negative values 0 is arbitrary

Answer 13

TRUE

Question 14

What is ratio data?

Answer 14

interval data with a natural data point

type of numerical data

Question 15

What is required in ratio data?

Answer 15

NO negative numbers

0 is a true zero

Question 16

Can you add and subtract types of categorical (ordinal, nominal) data?

Answer 16

NO

Question 17

What is an alternative hypothesis?

Answer 17

statement that there is a difference between 2 events (treatments, tests, etc)

Question 18

What is the null hypothesis?

Answer 18

statement that there is no difference between two events

Question 19

What is statistical significance?

Answer 19

the probability of rejecting the null hypothesis due to chance alone (given that the null hypothesis is true)

usually expressed as a p value

Question 20

Regarding accepting and rejecting hypotheses, what can we NOT do?

Answer 20

accept the alternative hypothesis
accept the null hypothesis
reject the alternative hypothesis

Question 21

Statistical significance does not necessarily equate to ______

Answer 21

clinical significance

Question 22

What is clinical significance?

Answer 22

the practical importance of a treatment effect - whether it has a real genuine, palpable, noticeable effect on daily life

Question 23

What are confounding factors?

Answer 23

additional variable that could influence results that are not considered in the subject population selection (unknown bias)

Question 24

What are potential confounders?

Answer 24

age
IQ
prior coursework
gender
outside work
marital status

Question 25

What are properties of a confounder?

Answer 25

exposure
independent of risk factor of disease
not in casual pathway