Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
17 Cards in this Set
- Front
- Back
|
Independent Variable
|
X= predictor= Exposure= independent variable
|
|
|
Dependent Variable
|
Y= outcome= Disease= response variable= dependent variable
|
|
|
Nominal Variable
|
Level of measurement scale.
Data by name alone, no consideration of magnitude or order. Ex- 1= Females 2= Males. Also dichotomous or binomial. Also called categorical Can only be discrete variables |
|
|
Ordinal Variable
|
Ordered catagorical variables.
Ordered or ranked categories but not necessarily in magnitude. Ex- 1= Freshman, 2= Sophomores Can be discrete or continuous |
|
|
Continuous Variable
|
May take any value. Ex- blood pressure, cholesterol
|
|
|
Discrete Variables
|
Counts.
Data with assigned order and magnitude but restricted to whole numbers. Nominal, ordinal, interval and ratio variables can be discrete |
|
|
Hierarchy of Variables
|
A variable can always be analyzed as if it were of a type further down the hierarchy, but not visa versa.
ratio>> interval >> ordinal >> nominal |
|
|
Measures of Central Tendency
|
1) Mean
2) Median 3) Mode |
|
|
Measures of Spread
|
1) Range
2) Variance 3) Standard Deviation |
|
|
Mean
|
Average, unique, simple, includes all numbers, affected by extremes
|
|
|
Median
|
Middle pt of data pts. Unique, simple NOT affected by extreme values.
|
|
|
Mode
|
Most appeared number. Can have none or more than one.
|
|
|
Range
|
Max- Min. Simple,sensitive to extreme values
|
|
|
Variance
|
Variance= SD^2
Uses all data points, always positive. Gives idea of data variability. |
|
|
Standard Deviation
|
Is the average deviation of the mean from the observations themselves.
Uses all data points, original units of data. |
|
|
Interval Variable
|
Based on variable having intervals of equal length or distance, like inches on a ruler.
Does not have an absolute zero point like ratio scale so total absence of attribute cannot be calibrated. Can be discrete or continuous Ex- Temperature and IQ |
|
|
Ratio Variable
|
Based on variable having intervals of equal length or distance, like inches on a ruler.
Does have an absolute zero point. Can be discrete or continous Ex- No. of cigarettes smoked per day |
