Intro to Biostatistics

Question 1

Examples of Descriptive statistics include represtation of data in what ways?

Answer 1

Clustered Column

Pie Chart

3-D Column

Question 2

What is a frequently used graphical display that is often used in medical literature?

Answer 2

1. A Study Design Flow Chart
2. Kaplan Meier Estimators
3. Forest Plots
4. Line Graphs
5. Histograms

Question 3

What does inferential Statistics allow researchers to do?

Answer 3

Generalize from our sample of data to a larger group or population

Question 4

What are inferential statistics used to determine?

Answer 4

The probability that a conclusion based on analysis of the data froma sample is true

Question 5

What are the measurements based on a sample of population subject to?

Answer 5

Random Error

Question 6

The ultimate goal of inferential statistis is what?

Answer 6

To be hightly specific about the effect random error has on our sample

Question 7

What does the ability to estimate how far you might be away from the true value depend on?

Answer 7

2 variables.

Question 8

What are the 2 variables that the ability to esimate in inferential statistics depends on?

Answer 8

1. The sample Size
2. The Standard Deviation (SD)

Question 9

Why is it so important to have a large sample size?

Answer 9

Because the larger the sample size, the greater the likelihood that our estimate will be close to the truth

Question 10

If there is relatively little variation found about the mean of the sample, whis is likely regarding the sample mean?

Answer 10

It is likeley that the sample mena will lie fairly close to the true value.

Question 11

What is a variable?

Answer 11

Whatever is being observed or measured

Question 12

A dependent variable is… ?

Answer 12

The outcome of interest and changes in response to some intervention

(changes in response to the Independent variable)

Question 13

An independent variable is…?

Answer 13

the intervention or what is being manipulated by the researcher

Question 14

Explain what a discrete variable is

Answer 14

A discrete variable can have only one of a limited set of values that are whole numbers

Question 15

What is a continuous variable?

Answer 15

A continous variable can take any value, within a defined range

Question 16

What is discrete data?

Answer 16

This data has only whole number values

Question 17

What is continuous data?

Answer 17

This data can take any value within a predetermined range of values

Question 18

Are many statistical techniques discrete or indiscrete?

Answer 18

Indiscrete

Question 19

There are 4 types of Data Sprinkles. What are they?

Answer 19

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

(These can be data or variables)

Question 20

1. Explain what a rate is
2. Explain what a proportion is
3. What is a percentage?

Answer 20

1. A fraction that contains a time component

Ex: 1/1000 people will develop pneumonia this year

2. A type of fraction in which the numerator is a subset of the denominator

Ex: 1/3

3. A form of proportion where the denominator is artificially set to equal 100

Question 21

A central or typical value for a propability distribtion (or, an average) is known as what?

Answer 21

Central Tendancy

Question 22

What is the term for the measure of central tendency for inteval and ratio data?

Answer 22

The mean

Question 23

1. The is the median when talking about central tendency?
2. What is an important use of the median?

Answer 23

1. It is the value that half of the data points are above and half are below
2. It is used as a measure of cntral tendency when the mean would be meaningless, as with ordinal data

Question 24

Define the “mode” in central tendency

Answer 24

• the only measure that may be used with nominal data
• consists of the most frequenly occuring category.

Question 25

What is nominal data derived from?

Answer 25

Qualitative measures

Question 26

Explain what the measure of dispersion is

Answer 26

It refers to how closely the data cluster around the measure of central tendency

Question 27

What is the term for the difference between the highest and lowest values?

Answer 27

The Range

Question 28

The variance is what?

Answer 28

It measure how far a set of numbers is spread out

Question 29

What does a small variance indicate?

Answer 29

that the data points are very close to the mean and each other

Question 30

Explain what the standard deviation is

Answer 30

- It is the square root of the variance of a random variable or statistical population. - The SD is expressed in the same usits as the original measurement

Question 31

The smaller the standard deviation, the closer the numbers are to the ?

Answer 31

mean