0701

Question 1

What are dichotomous variables?

Answer 1

Two possible variables, i.e. Yes/No, Dead/Alive, Employed/Unemployed, etc.

Question 2

What are two other terms for dichotomous variables?

Answer 2

Indicator or binary variables.

Question 3

What are categorical variables?

Answer 3

Variables with a fixed number of response options that have no inherent order to them, such as religious affiliation.

Question 4

What graphic best describes categorical variables?

Answer 4

A bar chart.

Question 5

What is another term for categorical variables?

Answer 5

Nominal variables.

Question 6

What are ordinal variables?

Answer 6

More that two variables and the variables have an order or implicit ranking, such as <30 minutes, 30-180 minutes, >180 minutes.

Question 7

What graphic best describes ordinal variables?

Answer 7

A histogram.

Question 8

What are continuous variables?

Answer 8

Variables that assume any value between a given minimum and a maximum. These are very common in biological measurements, such as systolic blood pressure or weight.

Question 9

What is another term for continuous variables?

Answer 9

Measurement variables.

Question 10

What graphic best describes a continuous variable?

Answer 10

A box and whisker plot.

Question 11

What are percentages also referred to as?

Answer 11

Frequencies.

Question 12

What is the mean?

Answer 12

Typical averaging.

Question 13

What is the median?

Answer 13

The center most value in odd numbers, the split between even numbers.

Question 14

x denotes what?

Answer 14

The variable we are analyzing.

Question 15

x with a line over it (x-bar) denotes what?

Answer 15

The mean.

Question 16

If there is an extreme difference between the mean and median, is the mean or median a better representation?

Answer 16

The median.

Question 17

If the is a typical value or central tendency, is the mean or median a better representation?

Answer 17

The mean.

Question 18

What is the sample variance formula?

Answer 18

Sigma (x-xbar)^2 divided by n-1.

Question 19

What is the standard deviation formula

Answer 19

The square root of the sample variance.

Question 20

What is the critical measure of variability and dispersion in data when we are looking at continuous measurements?

Answer 20

The standard deviation.

Question 21

What is the empirical rule approximates?

Answer 21

68%, 95%, and 99.7%.

Question 22

A symmetric distribution is one where?

Answer 22

The mean is equal to the median (bell-shaped curve), in which we’d find no outliers.

Question 23

How would we summarize the distribution of a symmetric distribution?

Answer 23

Sample mean and standard deviation.

Question 24

A skewed distribution is one where?

Answer 24

There are outliers.

Question 25

How would we summarize distribution of a skewed distribution?

Answer 25

Median and interquartile range.

Question 26

What part of the curve indicates the skewed distribution?

Answer 26

The tail, e.g., a right-skewed distribution would have the bulge on the left and the tail on the right.

Question 27

What type of exposure is genetics, ancestry, race and ethnicity?

Answer 27

Constituent exposures.

Question 28

What is the critical window of vulnerability?

Answer 28

An exposure occurs in the context of human development that is very important in terms of the health outcome.

Question 29

What are the three essential attributes of a cause?

Answer 29

Association, Time Order, and Direction.

Question 30

False explanations for association are?

Answer 30

Random error, Bias, Confounding, and Effect Measure Modification (EMM).

Question 31

What is confounding?

Answer 31

An outcome that is unequally distributed between comparison groups.

Question 32

What is Effect Measure Modification?

Answer 32

EMM is an outcome that ignores a third variable, i.e. exposure leads to a disease without considering the difference between men and women.

Question 33

What is the formula for outliers?

Answer 33

Q3+(1.5x1QR) and Q1-(1.5xIQR).

Question 34

What is the formula for determining IQR?

Answer 34

Q3-Q1=IQR.

Question 35

How is Q1 and Q3 determined?

Answer 35

They are defined as the median to the side of the Q2 median.

Question 36

How is Q2 determined?

Answer 36

It is the median.

Question 37

Outliers may be described in the context of standard deviation as?

Answer 37

The mean +/- three times the standard deviation, in each direction, e.g. 11+/- (3x13) 11+33=44, 11-33=-22.