BSSE

Question 1

What happens to PPV if disease prevalence increases?

Answer 1

PPV increases

Question 2

What happens to NPV if disease prevalence increases?

Answer 2

NPV decreases

Question 3

What happens to NPV if sensitivity increases?

Answer 3

NPV increases

Question 4

What happens to NPV if sensitivity decreases?

Answer 4

NPV decreases

Question 5

What happens to PPV if specificity increases?

Answer 5

PPV increases

Question 6

What happens to PPV if specificity decreases?

Answer 6

PPV decreases

Question 7

What is the equation for the false positive rate?

Answer 7

false positive / (false positive + true negative)

Question 8

What is the equation for the false negative rate?

Answer 8

false negative / (false negative + true positive)

Question 9

What is the equation for sensitivity?

Answer 9

TP/(TP+FN)

Question 10

What is the equation for specificity?

Answer 10

TN/(TN+FP)

Question 11

What is the equation for positive predictive value?

Answer 11

TP/(TP+FP)

If disease prevalence increases, PPV increases.

Question 12

What is the equation for negative predictive value?

Answer 12

TN/(TN+FN)

Sensitive test if negative, will rule the disease out.

Question 13

What does a specific test indicate if positive?

Answer 13

Will rule the disease in.

Question 14

What does specific test indicate if negative

Answer 14

Rule disease out

Question 15

PPV change with disease prevalence increase

Answer 15

PPV increases

Question 16

What happens to standard deviation if precision increases?

Answer 16

Decreases

Question 17

What happens to statistical power if precision increases?

Answer 17

Increases

Question 18

What does sensitivity describe?

Answer 18

Sensitivity describes how well a test can detect a specific disease/condition in people that actually have it.

Question 19

What does specificity describe?

Answer 19

Specificity describes the percentage of people who test negative for a specific disease among a group of people who do not have the disease.

Question 20

What is prevalence?

Answer 20

Number of people with an illness at a given time

Question 21

What is incidence?

Answer 21

Number of new cases at a given time

Question 22

If the incidence decreases, then prevalence

Answer 22

Decreases

Question 23

Can independent events be mutually exclusive?

Answer 23

No

Question 24

What defines two sets as non-mutually exclusive?

Answer 24

They share common elements

Question 25

What occurs in a type I error?

Answer 25

False positive

Question 26

What occurs in a type 2 error?

Answer 26

False negative

Question 27

What is the probability of getting Alpha level (usually 0.05)?

Answer 27

a type 1 error

Question 28

What is the probability of getting Beta level (often 0.2)?

Answer 28

a type 2 error

Question 29

What is the equation for power?

Answer 29

1 - beta

Question 30

What is the fraction of experiments in Power?

Answer 30

which you would expect to find a statistically significant result

Question 31

What is the equation for power related to positive and negative results?

Answer 31

TP / (TP + FN)

Question 32

What happens if a type 1 error is made?

Answer 32

Beta will increase

Question 33

If a type 1 error is made, power will _

Answer 33

Decrease (power=1-beta)

Question 34

When do you use a t-test?

Answer 34

When you have 2 groups and ONLY 2 groups!

Question 35

When do you use an ANOVA?

Answer 35

When you have three or more means.

Question 36

Central tendency is another term for...

Answer 36

Mean

Question 37

How are the mean, median and mode related in a normal distribution?

Answer 37

Mean=median=mode

Question 38

In a normal distribution, what is the 95% confidence interval in terms of standard deviation?

Answer 38

2 SD

Question 39

In a normal distribution, what is the 99% confidence interval in terms of standard deviation?

Answer 39

2.5 SD

Question 40

What is the equation for standard deviation?

Answer 40

sqrt of variance

Question 41

Why do we subtract 1 from the variance?

Answer 41

Lowers population, more conservative error value

Question 42

What is a positive skew?

Answer 42

More scores fall in the lower range, so the curve will have a positive skew when plotted.

Question 43

What is a negative skew?

Answer 43

More scores fall in the higher range, so the curve will have a negative skew when plotted.

Question 44

In a positive skew, how are mean, median, and mode related?

Answer 44

Mean > median > mode

Question 45

In a negative skew, how are mean, median, and mode related?

Answer 45

Mode > median > mean

Question 46

What kind of data is categorical?

Answer 46

Nominal, dichotomous, and ordinal.

Question 47

What is nominal data?

Answer 47

Examples include bungalow, condo, house.

Question 48

What is dichotomous data?

Answer 48

Examples include male/female.

Question 49

What is ordinal data?

Answer 49

Examples include not very much, a lot, etc.

Question 50

What type of data is continuous?

Answer 50

Interval and ratio.

Question 51

What is an example of interval data?

Answer 51

Temperature.

Question 52

For what data is mode the best measure of central tendency?

Answer 52

Nominal.

Question 53

When is mean the best measure of central tendency?

Answer 53

When data is continuous.

Question 54

What measure of central tendency is used for ordinal data?

Answer 54

Mode and median.

Question 55

What measure of central tendency is used for interval and ratio data?

Answer 55

Mean, median, or mode.

Question 56

How do you calculate SEM?

Answer 56

SD/square root of the sample set

Question 57

A 99% confidence interval is _ than a 95%.

Answer 57

Less precise

Question 58

A 99% confidence interval is _ than a 95%.

Answer 58

More Accurate

Question 59

What test is used for categorical data?

Answer 59

Chi square

Question 60

What test is used for continuous data?

Answer 60

T-test or Analysis of Variance (ANOVA)

Question 61

When do you use a Fisher's exact test?

Answer 61

When comparing proportions of two categories