What is a Multiple Linear 
Regression?
Welcome to this learning module on 
Multiple Linear Regression
In this presentation we will cover the following 
aspects of Multiple Regression:
In this presentation we will cover the following 
aspects of Multiple Regression: 
- Connection to Partial Correlation and ANCOVA
In this presentation we will cover the following 
aspects of Multiple Regression: 
- Connection to Partial Correlation and ANCOVA 
- Unique contribution of each variable
In this presentation we will cover the following 
aspects of Multiple Regression: 
- Connection to Partial Correlation and ANCOVA 
- Unique contribution of each variable 
- Contribution of all variables at the same time
In this presentation we will cover the following 
aspects of Multiple Regression: 
- Connection to Partial Correlation and ANCOVA 
- Unique contribution of each variable 
- Contribution of all variables at the same time 
- Type of data multiple regression can handle
In this presentation we will cover the following 
aspects of Multiple Regression: 
- Connection to Partial Correlation and ANCOVA 
- Unique contribution of each variable 
- Contribution of all variables at the same time 
- Type of data multiple regression can handle 
- Types of relationships multiple regression 
describes
In this presentation we will cover the following 
aspects of Multiple Regression: 
- Connection to Partial Correlation and ANCOVA 
- Unique contribution of each variable 
- Contribution of all variables at the same time 
- Type of data multiple regression can handle 
- Types of relationships multiple regression 
describes
In this presentation we will cover the following 
aspects of Multiple Regression: 
- Connection to Partial Correlation and ANCOVA 
- Unique contribution of each variable 
- Contribution of In all this variables presentation at the we same will 
time 
- Type of data multiple cover the regression concept of can Partial 
handle 
Correlation. 
- Types of relationships multiple regression 
describes
In this presentation we will cover the following 
aspects of Multiple Regression: 
- Connection to Partial Correlation and ANCOVA 
- Unique contribution of each variable 
- Contribution of all variables at the same time 
- Type of data multiple regression can handle 
- Types of relationships multiple regression 
describes 
After going through this 
presentation look at the 
presentation on Analysis of 
Covariance and consider 
what multiple regression 
and ANCOVA have in 
common.
In this presentation we will cover the following 
aspects of Multiple Regression: 
- Connection to Partial Correlation and ANCOVA 
- Unique contribution of each variable 
- Contribution of What all variables is a Partial at Correlation? 
the same time 
- Type of data multiple regression can handle 
- Types of relationships multiple regression 
describes
Partial correlation estimates the relationship 
between two variables while removing the 
influence of a third variable from the 
relationship.
Like in the example that follows,
Like in the example that follows, a Pearson Correlation 
between height and weight would yield a .825 
correlation.
Like in the example that follows, a Pearson Correlation 
between height and weight would yield a .825 
correlation. We might then control for gender (because 
we think being female or male has an effect on the 
relationship between height and weight).
However, when controlling for gender the correlation 
between height and weight drops to .770.
However, when controlling for gender the correlation 
between height and weight drops to .770. 
Individual Height (inches) Weight (pounds) Sex (1 – male, 2 – female) 
A 73 240 1 
B 70 210 1 
C 69 180 1 
D 68 160 1 
E 70 150 2 
F 68 140 2 
G 67 135 2 
H 62 120 2
However, when controlling for gender the correlation 
between height and weight drops to .770. 
Individual Height (inches) Weight (pounds) Sex (1 – male, 2 – female) 
A 73 240 1 
B 70 210 1 
C 69 180 1 
D 68 160 1 
E 70 150 2 
F 68 140 2 
G 67 135 2 
H 62 120 2
However, when controlling for gender the correlation 
between height and weight drops to .770. 
Individual Height (inches) Weight (pounds) Sex (1 – male, 2 – female) 
A 73 240 1 
B 70 210 1 
C 69 180 1 
D 68 160 1 
E 70 150 2 
F 68 140 2 
G 67 135 2 
H 62 120 2 
&
However, when controlling for gender the correlation 
between height and weight drops to .770. 
Individual Height (inches) Weight (pounds) Sex (1 – male, 2 – female) 
A 73 240 1 
B 70 210 1 
C 69 180 1 
D 68 160 1 
E 70 150 2 
F 68 140 2 
G 67 135 2 
H 62 120 2 
&
However, when controlling for gender the correlation 
between height and weight drops to .770. 
Individual Height (inches) Weight (pounds) Sex (1 – male, 2 – female) 
A 73 240 1 
B 70 210 1 
C 69 180 1 
D 68 160 1 
E 70 150 2 
F 68 140 2 
G 67 135 2 
H 62 120 2 
& controlling for
However, when controlling for gender the correlation 
between height and weight drops to .770. 
Individual Height (inches) Weight (pounds) Sex (1 – male, 2 – female) 
A 73 240 1 
B 70 210 1 
C 69 180 1 
D 68 160 1 
E 70 150 2 
F 68 140 2 
G 67 135 2 
H 62 120 2 
& controlling for
However, when controlling for gender the correlation 
between height and weight drops to .770. 
Individual Height (inches) Weight (pounds) Sex (1 – male, 2 – female) 
A 73 240 1 
B 70 210 1 
C 69 180 1 
D 68 160 1 
E 70 150 2 
F 68 140 2 
G 67 135 2 
H 62 120 2 
& controlling for = .770
This is very helpful because we may think two variables 
(height and weight) are highly correlated but we can 
determine if that correlation holds when we take out 
the effect of a third variable (gender).
While in partial correlation, only two variables are 
correlated while holding a third variable constant, in 
multiple regression several variables are grouped 
together to predict an outcome variable.
While in partial correlation, only two variables are 
correlated while holding a third variable constant, in 
multiple regression several variables are grouped 
together to predict an outcome variable 
Independent or 
Predictor Variables
While in partial correlation, only two variables are 
correlated while holding a third variable constant, in 
multiple regression several variables are grouped 
together to predict an outcome variable 
Independent or 
Predictor Variables 
Height
While in partial correlation, only two variables are 
correlated while holding a third variable constant, in 
multiple regression several variables are grouped 
together to predict an outcome variable 
Independent or 
Predictor Variables 
Height 
Gender
While in partial correlation, only two variables are 
correlated while holding a third variable constant, in 
multiple regression several variables are grouped 
together to predict an outcome variable 
Independent or 
Predictor Variables 
Height 
Gender 
Age
While in partial correlation, only two variables are 
correlated while holding a third variable constant, in 
multiple regression several variables are grouped 
together to predict an outcome variable 
Independent or 
Predictor Variables 
Height 
Gender 
Age 
Soda 
Drinking
While in partial correlation, only two variables are 
correlated while holding a third variable constant, in 
multiple regression several variables are grouped 
together to predict an outcome variable 
Independent or 
Predictor Variables 
Height 
Gender 
Age 
Soda 
Drinking 
Exercise
While in partial correlation, only two variables are 
correlated while holding a third variable constant, in 
multiple regression several variables are grouped 
together to predict an outcome variable 
Independent or 
Predictor Variables 
Height 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable
While in partial correlation, only two variables are 
correlated while holding a third variable constant, in 
multiple regression several variables are grouped 
together to predict an outcome variable 
Independent or 
Predictor Variables 
Height 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
Weight
While in partial correlation, only two variables are 
correlated while holding a third variable constant, in 
multiple regression several variables are grouped 
together to predict an outcome variable 
Independent or 
Predictor Variables 
Height 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
Weight 
all have an influence 
on . . .
While in partial correlation, only two variables are 
correlated while holding a third variable constant, in 
multiple regression several variables are grouped 
together to predict an outcome variable 
Independent or 
Predictor Variables 
Height 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
Weight 
all have an influence 
on . . .
While in partial correlation, only two variables are 
correlated while holding a third variable constant, in 
multiple regression several variables are grouped 
together to predict an outcome variable 
Independent or 
Predictor Variables 
Height 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
Weight 
all have an influence 
on . . .
While in partial correlation, only two variables are 
correlated while holding a third variable constant, in 
multiple regression several variables are grouped 
together to predict an outcome variable 
Independent or 
Predictor Variables 
Height 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
Weight 
all have an influence 
on . . .
While in partial correlation, only two variables are 
correlated while holding a third variable constant, in 
multiple regression several variables are grouped 
together to predict an outcome variable 
Independent or 
Predictor Variables 
Height 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
Weight 
all have an influence 
on . . .
While in partial correlation, only two variables are 
correlated while holding a third variable constant, in 
multiple regression several variables are grouped 
together to predict an outcome variable 
Independent or 
Predictor Variables 
Height 
Weight 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . .
In this presentation we will cover the following 
aspects of Multiple Regression: 
- Connection to Partial Correlation and ANCOVA 
- Unique contribution of each variable 
- Contribution of all variables at the same time 
- Type of data multiple regression can handle 
- Types of relationships multiple regression 
describes
Essentially, the group of predictors are all covariates to 
each other. 
Independent or 
Predictor Variables 
Height 
Weight 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . .
Meaning, 
Independent or 
Predictor Variables 
Height 
Weight 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . .
Meaning, for example, 
Independent or 
Predictor Variables 
Height 
Weight 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . .
Meaning, for example, that it is possible to identify the 
unique prediction power of height on weight 
Independent or 
Predictor Variables 
Height 
Weight 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . .
Meaning, for example, that it is possible to identify the 
unique prediction power of height on weight 
Independent or 
Predictor Variables 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
Height on . . . 
Weight
Meaning, for example, that it is possible to identify the 
unique prediction power of height on weight after 
you’ve taken out the influence of all of the other 
predictors. 
Independent or 
Predictor Variables 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
Height on . . . 
Weight
Meaning, for example, that it is possible to identify the 
unique prediction power of height on weight after 
you’ve taken out the influence of all of the other 
predictors. 
Independent or 
Predictor Variables 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
Height on . . . 
Weight
For example, 
Independent or 
Predictor Variables 
Height 
Weight 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . .
For example, here is the correlation between Height 
and Weight without controlling for all of the other 
variables. 
Independent or 
Predictor Variables 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
Height on . . . 
Weight
For example, here is the correlation between Height 
and Weight without controlling for all of the other 
variables. 
Independent or 
Predictor Variables 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
Height on . . . 
Weight 
Correlation = .825
However, 
Independent or 
Predictor Variables 
Height 
Weight 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . .
However, here is the correlation between Height and 
Weight after taking out the effect of all of the other 
variables. 
Independent or 
Predictor Variables 
Height 
Weight 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . .
However, here is the correlation between Height and 
Weight after taking out the effect of all of the other 
variables. 
Independent or 
Predictor Variables 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . . 
Weight 
Height
However, here is the correlation between Height and 
Weight after taking out the effect of all of the other 
variables. 
Independent or 
Predictor Variables 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
Height on . . . 
Weight 
Correlation = .601
However, here is the correlation between Height and 
Weight after taking out the effect of all of the other 
variables. 
Independent or 
Predictor Variables 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . . 
Weight 
Correlation = .601 
So, after eliminating the 
effect of gender, age, soda, 
and exercise on weight, the 
unique correlation that height 
shares with weight is .601. 
Height
Even though we were only correlating height and 
weight when we computed a correlation of .825,
Even though we were only correlating height and 
weight when we computed a correlation of .825, the 
other four variables still had an influence on weight.
Even though we were only correlating height and 
weight when we computed a correlation of .825, the 
other four variables still had an influence on weight. 
However, that influence was not accounted for and 
remained hidden.
With multiple regression we can control for these four 
variables and account for their influence
With multiple regression we can control for these four 
variables and account for their influence thus 
calculating the unique contribution height makes on 
weight without their influence being present.
We can do the same for any of these other variables. 
Like the relationship between Gender and Weight.
We can do the same for any of these other variables. 
Like the relationship between Gender and Weight. 
Independent or 
Predictor Variables 
Height 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . . 
Weight 
Gender
We can do the same for any of these other variables. 
Like the relationship between Gender and Weight. 
Independent or 
Predictor Variables 
Height 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . . 
Weight 
Gender 
Correlation = .701
But when you take out the influence of the other 
variables the correlation drops from .701 to .582.
BEFORE 
Independent or 
Predictor Variables 
Height 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . . 
Weight 
Gender 
Correlation = .701
AFTER
AFTER 
Independent or 
Predictor Variables 
Height 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . . 
Weight 
Gender
AFTER 
Independent or 
Predictor Variables 
Height 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . . 
Weight 
Gender 
Correlation = .582
Here is the correlation between age and weight before 
you take out the effect of the other variables:
Here is the correlation between age and weight before 
you take out the effect of the other variables: 
Independent or 
Predictor Variables 
Height 
Gender 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . . 
Age Weight
Here is the correlation between age and weight before 
you take out the effect of the other variables: 
Independent or 
Predictor Variables 
Height 
Gender 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . . 
Age Weight Correlation = .435
The correlation drops from .435 to .385 after taking out 
the influence of the other variables:
The correlation drops from .435 to .385 after taking out 
the influence of the other variables: 
Independent or 
Predictor Variables 
Height 
Gender 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . . 
Age Weight
The correlation drops from .435 to .385 after taking out 
the influence of the other variables: 
Independent or 
Predictor Variables 
Height 
Gender 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . . 
Age Weight Correlation = .385
In this presentation we will cover the following 
aspects of Multiple Regression: 
- Connection to Partial Correlation and ANCOVA 
- Unique contribution of each variable 
- Contribution of all variables at the same time 
- Type of data multiple regression can handle 
- Types of relationships multiple regression 
describes
Beyond estimating the unique power of each predictor,
Beyond estimating the unique power of each predictor, 
multiple regression also estimates the combined power 
of the group of predictors.
Beyond estimating the unique power of each predictor, 
multiple regression also estimates the combined power 
of the group of predictors.
Beyond estimating the unique power of each predictor, 
multiple regression also estimates the combined power 
of the group of predictors. 
Independent or 
Predictor Variables 
Height 
Weight 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable
Beyond estimating the unique power of each predictor, 
multiple regression also estimates the combined power 
of the group of predictors. 
Independent or 
Predictor Variables 
Height 
Weight 
Gender 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
Combined 
Correlation 
= .982
In this presentation we will cover the following 
aspects of Multiple Regression: 
- Connection to Partial Correlation and ANCOVA 
- Unique contribution of each variable 
- Contribution of all variables at the same time 
- Type of data multiple regression can handle 
- Types of relationships multiple regression 
describes
Multiple regression can estimate the effects of 
continuous and categorical variables in the same 
model.
Multiple regression can estimate the effects of 
continuous and categorical variables in the same 
model. 
Independent or 
Predictor Variables 
Height 
Dependent, Response 
or Outcome Variable 
Gender 
Age 
Soda 
Drinking 
Exercise 
Weight
Multiple regression can estimate the effects of 
continuous and categorical variables in the same 
model. 
Independent or 
Predictor Variables 
Height 
Height is represented by continuous data – 
because height can take on any value 
between two points in inches or centimeters. 
Dependent, Response 
or Outcome Variable 
Gender 
Age 
Soda 
Drinking 
Exercise 
Weight
Multiple regression can estimate the effects of 
continuous and categorical variables in the same 
model.
Multiple regression can estimate the effects of 
continuous and categorical variables in the same 
model. 
Independent or 
Predictor Variables 
Height 
Age 
Soda 
Drinking 
Exercise 
Dependent, Response 
or Outcome Variable 
all have an influence 
on . . . 
Weight 
Gender 
Gender is a represented by categorical data 
– because gender can take on two values 
(female or male)
In this presentation we will cover the following 
aspects of Multiple Regression: 
- Connection to Partial Correlation and ANCOVA 
- Unique contribution of each variable 
- Contribution of all variables at the same time 
- Type of data multiple regression can handle 
- Types of relationships multiple regression 
describes
Multiple regression can describe or estimate 
linear relationships like average monthly 
temperature and ice cream sales:
Multiple regression can describe or estimate 
linear relationships like average monthly 
temperature and ice cream sales: 
700 
600 
500 
400 
300 
200 
100 
0 
0 20 40 60 80 100 120 
Ave Monthly Temperature 
Average Monthly Ice Cream Sales
Multiple regression can describe or estimate 
linear relationships like average monthly 
temperature and ice cream sales: 
700 
600 
500 
400 
300 
200 
100 
0 
0 20 40 60 80 100 120 
Ave Monthly Temperature 
Average Monthly Ice Cream Sales
It can also describe or estimate curvilinear 
relationships.
For example,
For example, what if in our fantasy world the temperature 
reached 100 degrees and then 120 degrees. Let’s say with such 
extreme temperatures ice cream sales actually dip as consumers 
seek out products like electrolyte-enhanced drinks or slushies.
Then the relationship might look like this:
Then the relationship might look like this: 
700 
600 
500 
400 
300 
200 
100 
0 
0 20 40 60 80 100 120 
Ave Monthly Temperature 
Average Monthly Ice Cream Sales
Then the relationship might look like this: 
700 
600 
500 
400 
300 
200 
100 
0 
0 20 40 60 80 100 120 
Ave Monthly Temperature 
Average Monthly Ice Cream Sales 
This is an example of a 
Curvilinear 
Relationship
In summary,
In summary, Multiple Regression is like single linear 
regression but instead of determining the predictive 
power of one variable (temperature) on another 
variable (ice cream sales) we consider the predictive 
power of other variables (such as socio-economic status 
or age).
With multiple regression you can estimate the 
predictive power of many variables on a certain 
outcome,
With multiple regression you can estimate the 
predictive power of many variables on a certain 
outcome, as well as the unique influence each single 
variable makes on that outcome after taking out the 
influence of all of the other variables.

Multiple linear regression

  • 1.
    What is aMultiple Linear Regression?
  • 2.
    Welcome to thislearning module on Multiple Linear Regression
  • 3.
    In this presentationwe will cover the following aspects of Multiple Regression:
  • 4.
    In this presentationwe will cover the following aspects of Multiple Regression: - Connection to Partial Correlation and ANCOVA
  • 5.
    In this presentationwe will cover the following aspects of Multiple Regression: - Connection to Partial Correlation and ANCOVA - Unique contribution of each variable
  • 6.
    In this presentationwe will cover the following aspects of Multiple Regression: - Connection to Partial Correlation and ANCOVA - Unique contribution of each variable - Contribution of all variables at the same time
  • 7.
    In this presentationwe will cover the following aspects of Multiple Regression: - Connection to Partial Correlation and ANCOVA - Unique contribution of each variable - Contribution of all variables at the same time - Type of data multiple regression can handle
  • 8.
    In this presentationwe will cover the following aspects of Multiple Regression: - Connection to Partial Correlation and ANCOVA - Unique contribution of each variable - Contribution of all variables at the same time - Type of data multiple regression can handle - Types of relationships multiple regression describes
  • 9.
    In this presentationwe will cover the following aspects of Multiple Regression: - Connection to Partial Correlation and ANCOVA - Unique contribution of each variable - Contribution of all variables at the same time - Type of data multiple regression can handle - Types of relationships multiple regression describes
  • 10.
    In this presentationwe will cover the following aspects of Multiple Regression: - Connection to Partial Correlation and ANCOVA - Unique contribution of each variable - Contribution of In all this variables presentation at the we same will time - Type of data multiple cover the regression concept of can Partial handle Correlation. - Types of relationships multiple regression describes
  • 11.
    In this presentationwe will cover the following aspects of Multiple Regression: - Connection to Partial Correlation and ANCOVA - Unique contribution of each variable - Contribution of all variables at the same time - Type of data multiple regression can handle - Types of relationships multiple regression describes After going through this presentation look at the presentation on Analysis of Covariance and consider what multiple regression and ANCOVA have in common.
  • 12.
    In this presentationwe will cover the following aspects of Multiple Regression: - Connection to Partial Correlation and ANCOVA - Unique contribution of each variable - Contribution of What all variables is a Partial at Correlation? the same time - Type of data multiple regression can handle - Types of relationships multiple regression describes
  • 13.
    Partial correlation estimatesthe relationship between two variables while removing the influence of a third variable from the relationship.
  • 14.
    Like in theexample that follows,
  • 15.
    Like in theexample that follows, a Pearson Correlation between height and weight would yield a .825 correlation.
  • 16.
    Like in theexample that follows, a Pearson Correlation between height and weight would yield a .825 correlation. We might then control for gender (because we think being female or male has an effect on the relationship between height and weight).
  • 17.
    However, when controllingfor gender the correlation between height and weight drops to .770.
  • 18.
    However, when controllingfor gender the correlation between height and weight drops to .770. Individual Height (inches) Weight (pounds) Sex (1 – male, 2 – female) A 73 240 1 B 70 210 1 C 69 180 1 D 68 160 1 E 70 150 2 F 68 140 2 G 67 135 2 H 62 120 2
  • 19.
    However, when controllingfor gender the correlation between height and weight drops to .770. Individual Height (inches) Weight (pounds) Sex (1 – male, 2 – female) A 73 240 1 B 70 210 1 C 69 180 1 D 68 160 1 E 70 150 2 F 68 140 2 G 67 135 2 H 62 120 2
  • 20.
    However, when controllingfor gender the correlation between height and weight drops to .770. Individual Height (inches) Weight (pounds) Sex (1 – male, 2 – female) A 73 240 1 B 70 210 1 C 69 180 1 D 68 160 1 E 70 150 2 F 68 140 2 G 67 135 2 H 62 120 2 &
  • 21.
    However, when controllingfor gender the correlation between height and weight drops to .770. Individual Height (inches) Weight (pounds) Sex (1 – male, 2 – female) A 73 240 1 B 70 210 1 C 69 180 1 D 68 160 1 E 70 150 2 F 68 140 2 G 67 135 2 H 62 120 2 &
  • 22.
    However, when controllingfor gender the correlation between height and weight drops to .770. Individual Height (inches) Weight (pounds) Sex (1 – male, 2 – female) A 73 240 1 B 70 210 1 C 69 180 1 D 68 160 1 E 70 150 2 F 68 140 2 G 67 135 2 H 62 120 2 & controlling for
  • 23.
    However, when controllingfor gender the correlation between height and weight drops to .770. Individual Height (inches) Weight (pounds) Sex (1 – male, 2 – female) A 73 240 1 B 70 210 1 C 69 180 1 D 68 160 1 E 70 150 2 F 68 140 2 G 67 135 2 H 62 120 2 & controlling for
  • 24.
    However, when controllingfor gender the correlation between height and weight drops to .770. Individual Height (inches) Weight (pounds) Sex (1 – male, 2 – female) A 73 240 1 B 70 210 1 C 69 180 1 D 68 160 1 E 70 150 2 F 68 140 2 G 67 135 2 H 62 120 2 & controlling for = .770
  • 25.
    This is veryhelpful because we may think two variables (height and weight) are highly correlated but we can determine if that correlation holds when we take out the effect of a third variable (gender).
  • 26.
    While in partialcorrelation, only two variables are correlated while holding a third variable constant, in multiple regression several variables are grouped together to predict an outcome variable.
  • 27.
    While in partialcorrelation, only two variables are correlated while holding a third variable constant, in multiple regression several variables are grouped together to predict an outcome variable Independent or Predictor Variables
  • 28.
    While in partialcorrelation, only two variables are correlated while holding a third variable constant, in multiple regression several variables are grouped together to predict an outcome variable Independent or Predictor Variables Height
  • 29.
    While in partialcorrelation, only two variables are correlated while holding a third variable constant, in multiple regression several variables are grouped together to predict an outcome variable Independent or Predictor Variables Height Gender
  • 30.
    While in partialcorrelation, only two variables are correlated while holding a third variable constant, in multiple regression several variables are grouped together to predict an outcome variable Independent or Predictor Variables Height Gender Age
  • 31.
    While in partialcorrelation, only two variables are correlated while holding a third variable constant, in multiple regression several variables are grouped together to predict an outcome variable Independent or Predictor Variables Height Gender Age Soda Drinking
  • 32.
    While in partialcorrelation, only two variables are correlated while holding a third variable constant, in multiple regression several variables are grouped together to predict an outcome variable Independent or Predictor Variables Height Gender Age Soda Drinking Exercise
  • 33.
    While in partialcorrelation, only two variables are correlated while holding a third variable constant, in multiple regression several variables are grouped together to predict an outcome variable Independent or Predictor Variables Height Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable
  • 34.
    While in partialcorrelation, only two variables are correlated while holding a third variable constant, in multiple regression several variables are grouped together to predict an outcome variable Independent or Predictor Variables Height Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable Weight
  • 35.
    While in partialcorrelation, only two variables are correlated while holding a third variable constant, in multiple regression several variables are grouped together to predict an outcome variable Independent or Predictor Variables Height Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable Weight all have an influence on . . .
  • 36.
    While in partialcorrelation, only two variables are correlated while holding a third variable constant, in multiple regression several variables are grouped together to predict an outcome variable Independent or Predictor Variables Height Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable Weight all have an influence on . . .
  • 37.
    While in partialcorrelation, only two variables are correlated while holding a third variable constant, in multiple regression several variables are grouped together to predict an outcome variable Independent or Predictor Variables Height Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable Weight all have an influence on . . .
  • 38.
    While in partialcorrelation, only two variables are correlated while holding a third variable constant, in multiple regression several variables are grouped together to predict an outcome variable Independent or Predictor Variables Height Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable Weight all have an influence on . . .
  • 39.
    While in partialcorrelation, only two variables are correlated while holding a third variable constant, in multiple regression several variables are grouped together to predict an outcome variable Independent or Predictor Variables Height Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable Weight all have an influence on . . .
  • 40.
    While in partialcorrelation, only two variables are correlated while holding a third variable constant, in multiple regression several variables are grouped together to predict an outcome variable Independent or Predictor Variables Height Weight Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . .
  • 41.
    In this presentationwe will cover the following aspects of Multiple Regression: - Connection to Partial Correlation and ANCOVA - Unique contribution of each variable - Contribution of all variables at the same time - Type of data multiple regression can handle - Types of relationships multiple regression describes
  • 42.
    Essentially, the groupof predictors are all covariates to each other. Independent or Predictor Variables Height Weight Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . .
  • 43.
    Meaning, Independent or Predictor Variables Height Weight Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . .
  • 44.
    Meaning, for example, Independent or Predictor Variables Height Weight Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . .
  • 45.
    Meaning, for example,that it is possible to identify the unique prediction power of height on weight Independent or Predictor Variables Height Weight Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . .
  • 46.
    Meaning, for example,that it is possible to identify the unique prediction power of height on weight Independent or Predictor Variables Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence Height on . . . Weight
  • 47.
    Meaning, for example,that it is possible to identify the unique prediction power of height on weight after you’ve taken out the influence of all of the other predictors. Independent or Predictor Variables Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence Height on . . . Weight
  • 48.
    Meaning, for example,that it is possible to identify the unique prediction power of height on weight after you’ve taken out the influence of all of the other predictors. Independent or Predictor Variables Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence Height on . . . Weight
  • 49.
    For example, Independentor Predictor Variables Height Weight Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . .
  • 50.
    For example, hereis the correlation between Height and Weight without controlling for all of the other variables. Independent or Predictor Variables Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence Height on . . . Weight
  • 51.
    For example, hereis the correlation between Height and Weight without controlling for all of the other variables. Independent or Predictor Variables Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence Height on . . . Weight Correlation = .825
  • 52.
    However, Independent or Predictor Variables Height Weight Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . .
  • 53.
    However, here isthe correlation between Height and Weight after taking out the effect of all of the other variables. Independent or Predictor Variables Height Weight Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . .
  • 54.
    However, here isthe correlation between Height and Weight after taking out the effect of all of the other variables. Independent or Predictor Variables Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . . Weight Height
  • 55.
    However, here isthe correlation between Height and Weight after taking out the effect of all of the other variables. Independent or Predictor Variables Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence Height on . . . Weight Correlation = .601
  • 56.
    However, here isthe correlation between Height and Weight after taking out the effect of all of the other variables. Independent or Predictor Variables Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . . Weight Correlation = .601 So, after eliminating the effect of gender, age, soda, and exercise on weight, the unique correlation that height shares with weight is .601. Height
  • 57.
    Even though wewere only correlating height and weight when we computed a correlation of .825,
  • 58.
    Even though wewere only correlating height and weight when we computed a correlation of .825, the other four variables still had an influence on weight.
  • 59.
    Even though wewere only correlating height and weight when we computed a correlation of .825, the other four variables still had an influence on weight. However, that influence was not accounted for and remained hidden.
  • 60.
    With multiple regressionwe can control for these four variables and account for their influence
  • 61.
    With multiple regressionwe can control for these four variables and account for their influence thus calculating the unique contribution height makes on weight without their influence being present.
  • 62.
    We can dothe same for any of these other variables. Like the relationship between Gender and Weight.
  • 63.
    We can dothe same for any of these other variables. Like the relationship between Gender and Weight. Independent or Predictor Variables Height Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . . Weight Gender
  • 64.
    We can dothe same for any of these other variables. Like the relationship between Gender and Weight. Independent or Predictor Variables Height Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . . Weight Gender Correlation = .701
  • 65.
    But when youtake out the influence of the other variables the correlation drops from .701 to .582.
  • 66.
    BEFORE Independent or Predictor Variables Height Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . . Weight Gender Correlation = .701
  • 67.
  • 68.
    AFTER Independent or Predictor Variables Height Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . . Weight Gender
  • 69.
    AFTER Independent or Predictor Variables Height Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . . Weight Gender Correlation = .582
  • 70.
    Here is thecorrelation between age and weight before you take out the effect of the other variables:
  • 71.
    Here is thecorrelation between age and weight before you take out the effect of the other variables: Independent or Predictor Variables Height Gender Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . . Age Weight
  • 72.
    Here is thecorrelation between age and weight before you take out the effect of the other variables: Independent or Predictor Variables Height Gender Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . . Age Weight Correlation = .435
  • 73.
    The correlation dropsfrom .435 to .385 after taking out the influence of the other variables:
  • 74.
    The correlation dropsfrom .435 to .385 after taking out the influence of the other variables: Independent or Predictor Variables Height Gender Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . . Age Weight
  • 75.
    The correlation dropsfrom .435 to .385 after taking out the influence of the other variables: Independent or Predictor Variables Height Gender Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . . Age Weight Correlation = .385
  • 76.
    In this presentationwe will cover the following aspects of Multiple Regression: - Connection to Partial Correlation and ANCOVA - Unique contribution of each variable - Contribution of all variables at the same time - Type of data multiple regression can handle - Types of relationships multiple regression describes
  • 77.
    Beyond estimating theunique power of each predictor,
  • 78.
    Beyond estimating theunique power of each predictor, multiple regression also estimates the combined power of the group of predictors.
  • 79.
    Beyond estimating theunique power of each predictor, multiple regression also estimates the combined power of the group of predictors.
  • 80.
    Beyond estimating theunique power of each predictor, multiple regression also estimates the combined power of the group of predictors. Independent or Predictor Variables Height Weight Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable
  • 81.
    Beyond estimating theunique power of each predictor, multiple regression also estimates the combined power of the group of predictors. Independent or Predictor Variables Height Weight Gender Age Soda Drinking Exercise Dependent, Response or Outcome Variable Combined Correlation = .982
  • 82.
    In this presentationwe will cover the following aspects of Multiple Regression: - Connection to Partial Correlation and ANCOVA - Unique contribution of each variable - Contribution of all variables at the same time - Type of data multiple regression can handle - Types of relationships multiple regression describes
  • 83.
    Multiple regression canestimate the effects of continuous and categorical variables in the same model.
  • 84.
    Multiple regression canestimate the effects of continuous and categorical variables in the same model. Independent or Predictor Variables Height Dependent, Response or Outcome Variable Gender Age Soda Drinking Exercise Weight
  • 85.
    Multiple regression canestimate the effects of continuous and categorical variables in the same model. Independent or Predictor Variables Height Height is represented by continuous data – because height can take on any value between two points in inches or centimeters. Dependent, Response or Outcome Variable Gender Age Soda Drinking Exercise Weight
  • 86.
    Multiple regression canestimate the effects of continuous and categorical variables in the same model.
  • 87.
    Multiple regression canestimate the effects of continuous and categorical variables in the same model. Independent or Predictor Variables Height Age Soda Drinking Exercise Dependent, Response or Outcome Variable all have an influence on . . . Weight Gender Gender is a represented by categorical data – because gender can take on two values (female or male)
  • 88.
    In this presentationwe will cover the following aspects of Multiple Regression: - Connection to Partial Correlation and ANCOVA - Unique contribution of each variable - Contribution of all variables at the same time - Type of data multiple regression can handle - Types of relationships multiple regression describes
  • 89.
    Multiple regression candescribe or estimate linear relationships like average monthly temperature and ice cream sales:
  • 90.
    Multiple regression candescribe or estimate linear relationships like average monthly temperature and ice cream sales: 700 600 500 400 300 200 100 0 0 20 40 60 80 100 120 Ave Monthly Temperature Average Monthly Ice Cream Sales
  • 91.
    Multiple regression candescribe or estimate linear relationships like average monthly temperature and ice cream sales: 700 600 500 400 300 200 100 0 0 20 40 60 80 100 120 Ave Monthly Temperature Average Monthly Ice Cream Sales
  • 92.
    It can alsodescribe or estimate curvilinear relationships.
  • 93.
  • 94.
    For example, whatif in our fantasy world the temperature reached 100 degrees and then 120 degrees. Let’s say with such extreme temperatures ice cream sales actually dip as consumers seek out products like electrolyte-enhanced drinks or slushies.
  • 95.
    Then the relationshipmight look like this:
  • 96.
    Then the relationshipmight look like this: 700 600 500 400 300 200 100 0 0 20 40 60 80 100 120 Ave Monthly Temperature Average Monthly Ice Cream Sales
  • 97.
    Then the relationshipmight look like this: 700 600 500 400 300 200 100 0 0 20 40 60 80 100 120 Ave Monthly Temperature Average Monthly Ice Cream Sales This is an example of a Curvilinear Relationship
  • 98.
  • 99.
    In summary, MultipleRegression is like single linear regression but instead of determining the predictive power of one variable (temperature) on another variable (ice cream sales) we consider the predictive power of other variables (such as socio-economic status or age).
  • 100.
    With multiple regressionyou can estimate the predictive power of many variables on a certain outcome,
  • 101.
    With multiple regressionyou can estimate the predictive power of many variables on a certain outcome, as well as the unique influence each single variable makes on that outcome after taking out the influence of all of the other variables.