Evidence Based-Approaches: Concepts of Biostatistics

Question 1

Descriptive Statistics

Answer 1

Process of describing data; taking raw data and providing summarizing info or depicting data through figures

Question 2

Sample

Answer 2

Small subset of a population

Question 3

Population

Answer 3

The entire group that you want to draw conclusions about

Question 4

Inferential Statistics

Answer 4

Builds on descriptive statistics and allows researchers to draw conclusions based on info collected from the sample

Question 5

Variables

Answer 5

Characteristics that is of most interest of the subjects

Question 6

Statistic

Answer 6

A summarizing characteristic of sample’s variable

Question 7

Parameters

Answer 7

Summary attributes of a population

Question 8

Nominal Variables

Answer 8

Categories of the variable that have no order

Question 9

Dichotomous Variables

Answer 9

Variables that have only 2 possible variables

Question 10

Ordinal Variables

Answer 10

Categories of the variables that have an inherent order

Question 11

Continuous Variables

Answer 11

Variables that can take any value between a min and max value

Question 12

Interval Variables

Answer 12

Variables that have a distinct order and clearly defined intervals; lack a true 0. Also fails to reveal ratios of amounts.

Question 13

Ratio Variables

Answer 13

Variables that have a distinct order and clearly defined intervals; have a true 0. Variables act as true ratios of one another

Question 14

Frequency Tables

Answer 14

Used for nominal and ordinal data. Give information on frequency, relative frequency, cumulative frequency, and cumulative relative frequency.

Question 15

Measures of Central Tendency

Answer 15

Gives single values that describe the entire data for continuous variables

Question 16

Mean

Answer 16

Arithmetic average of the data. The sum of total values divided by the number of data values

Question 17

Median

Answer 17

Middle value of the data set

Question 18

Mode

Answer 18

Most common value of the data set

Question 19

Measures of Variability

Answer 19

Provides information on the spread of the data set

Question 20

Variance

Answer 20

Standard deviation squared

Question 21

Standard Deviation

Answer 21

A measure of how dispersed the data is in relation to the mean

Question 22

25% Quartile

Answer 22

Value between the median and lowest value

Question 23

75% Quartile

Answer 23

Value between the median and highest value

Question 24

Interquartile Range

Answer 24

75% Quartile -25% Quartile

Question 25

Range

Answer 25

Spectrum of values between highest and lowest value

Question 26

Probability

Answer 26

The numerical value applied to the likelihood for the occurrence of an event. All are proportions and range between 0 and 1.

Question 27

Conditional Probability

Answer 27

Assessing the probability of a characteristic given another characteristic

Question 28

Indepedence

Answer 28

A circumstance when the probability of one event does not have an impact on the probability of another event.

Question 29

Binomial Distribution

Answer 29

Model of the distribution of a dichotomous outcome variable

Question 30

Normal Distribution

Answer 30

Gaussian Distribution; model of the distribution of a continuous outcome variable

Question 31

Parametric Tests

Answer 31

Tests that depend on assumptions about the underlying distribution

Question 32

Normal Distribution Key Characteristics

Answer 32

- mean, mode and median are all the same and located in the center of the distribution - distribution is symmetric and not skewed - theoretical range extends horizontally from positive infinity to negative infinity - Only 2 parameters are necessary to describe a normal distribution: standard deviation and mean - area under the curve is exactly 1

Question 33

Central Limit Theorem

Answer 33

With repeated sampling, the individual mean calculations of samples form a normal distribution

Question 34

Null Hypothesis

Answer 34

Precise Statement; H0

Question 35

Alternative Hypothesis

Answer 35

More ambiguous statements that rivals the null hypothesis

Question 36

P-values

Answer 36

Probability values that measure the likelihood of obtaining the observed statistic or more extreme values when the null hypothesis is true

Question 37

Level of Significance

Answer 37

Alpha; Benchmark for rejection

Question 38

One-sided Test

Answer 38

Sample deviating from the null hypothesis conditions in one specific direction

Question 39

Two-sided Test

Answer 39

Does not specify directionality of sample

Question 40

Reject the Null Hypothesis

Answer 40

Less than alpha

Question 41

Fail to Reject the Null Hypothesis

Answer 41

Greater than alpha

Question 42

One Sample Z-Tests

Answer 42

Form of hypothesis testing that is performed on a continuous response variable.

Question 43

Degrees of Freedom

Answer 43

Number of observations - x

Question 44

Type I Error

Answer 44

Rejecting a true null hypothesis

Question 45

Type II Error

Answer 45

Failing to reject a false null hypothesis (what researchers prefer)