Association, Correlation, and Linear Regression Flashcards
1
Q
Scatter plot
- Variable x variable
- Both _
A
Quantitative
2
Q
Association
- (as x increases y increases) or – (as x increases y decreases)
- _
- Linear
- Straight
- Curved
- _
- Strong
- Moderate
- Weak
- Interesting outliers
A
Form, trend
3
Q
_ _
- Independent
- X axis
A
Explanatory variable
4
Q
_ _
- Dependent
- Y axis
A
Response variable
5
Q
Correlation
- Correlation coefficient (r) [-1,1]
- (_ slope)
- – (_ slope)
- 0
A
Positive, negative
6
Q
Coefficient of determination (r^2) [0,1]
A
% of the variance in y can be explained by the linear regression of y and x
7
Q
Prediction capability
A
Strong
Weak
Moderate
8
Q
Slope
A
rSy/Sx
9
Q
- Line of best fit
- Least residual
- Best predictor
- Stat, calc, linear regression
- Carrot over predicted in model
A
Least squares regression line
10
Q
Linear
- Scatter plot looks _
- _ pattern in residual plot
- Lresid x Ln
A
Linear, no
11
Q
Make linear
- Try pairs
- Translate
- If x is time then try _
- If both not time then try _
- Check residual plot for no pattern
- Make sure to put revisions in place of y and x when describing the context of r^2
A
Log(y), log(x) log(y)
12
Q
Data outside of range
A
Extrapolation
13
Q
X value far from average x
A
High leverage
14
Q
Omitting it would give a different model
A
Influential/outlier
15
Q
Alternative variable
A
Lurking variable
