BIOSTATS - EXAM 1 QUESTIONS AND ANSWERS
What is descriptive statistics?
Describes data that we collect or observe
(i.e. empirical data)
Concerned with presentation, organization and summarization of data
Descriptive Statistics - Examples (3)
Frequencies and associated percentages
Average or range of outcomes
Pie charts, bar graphs, or other visual representation of data
What is Inferential Statistics?
A range of procedures/statistical tests
(e.g. t-test, analysis of variance, or chi-square test, multiple regression analysis)
Allows us to generalize from our sample of data to a larger group of subjects
(Draw a sample from a population, not dealing with the entire population)
Inferential Statistics - Examples
- Can be Parametric vs. Non-parametric statistics
Population: parameter mean, standard deviation
Sample: statistics (mean; standard deviation)
...are examples of (differential/inferential) statistics
,What is a Discrete Variable?
Examples?
characterized by gaps or interruptions
"qualitative data"
Discrete variables have values that can only assume whole numbers
What is a Continuous Variable?
Examples?
Continuous variable has no gaps or interruptions
Takes any value within a defined range
"quantitative data"
Discrete data chart
Continuous data chart
, Ex: Is numbers of patients discrete or continuous?
discrete
Ex: Is Gender discrete or continuous?
discrete
Ex: Is temperature of fever discrete or continuous?
continuous
Ex: Is mortality status discrete or continuous?
discrete
Dependent variable
The outcome factor;
the variable that may change in response to manipulations of the independent
variable.
Independent Variable
The experimental factor that is manipulated;
the variable whose effect is being studied
Can be manipulated to change the outcome
Nominal scale
Named categories with no implied order among the categories
Attributes are only named; weakest
Ordinal Scale
Named categories with order.
What is descriptive statistics?
Describes data that we collect or observe
(i.e. empirical data)
Concerned with presentation, organization and summarization of data
Descriptive Statistics - Examples (3)
Frequencies and associated percentages
Average or range of outcomes
Pie charts, bar graphs, or other visual representation of data
What is Inferential Statistics?
A range of procedures/statistical tests
(e.g. t-test, analysis of variance, or chi-square test, multiple regression analysis)
Allows us to generalize from our sample of data to a larger group of subjects
(Draw a sample from a population, not dealing with the entire population)
Inferential Statistics - Examples
- Can be Parametric vs. Non-parametric statistics
Population: parameter mean, standard deviation
Sample: statistics (mean; standard deviation)
...are examples of (differential/inferential) statistics
,What is a Discrete Variable?
Examples?
characterized by gaps or interruptions
"qualitative data"
Discrete variables have values that can only assume whole numbers
What is a Continuous Variable?
Examples?
Continuous variable has no gaps or interruptions
Takes any value within a defined range
"quantitative data"
Discrete data chart
Continuous data chart
, Ex: Is numbers of patients discrete or continuous?
discrete
Ex: Is Gender discrete or continuous?
discrete
Ex: Is temperature of fever discrete or continuous?
continuous
Ex: Is mortality status discrete or continuous?
discrete
Dependent variable
The outcome factor;
the variable that may change in response to manipulations of the independent
variable.
Independent Variable
The experimental factor that is manipulated;
the variable whose effect is being studied
Can be manipulated to change the outcome
Nominal scale
Named categories with no implied order among the categories
Attributes are only named; weakest
Ordinal Scale
Named categories with order.
