Edf 5400
Download
1 / 66

EDF 5400 - PowerPoint PPT Presentation


  • 127 Views
  • Uploaded on

EDF 5400. Albert Oosterhof September 27 and October 2. Create the scatterplot for these scores, then plot the regression line.... Supplement 8. Adding the regression line to the scatterplot. A scatterplot and regression line typically involves more than five cases.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' EDF 5400' - sakina


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Edf 5400

EDF 5400

Albert OosterhofSeptember 27 and October 2





Here is the regression equation for predicting posttest scores from pretest scores supplement 9
Here is the regression equation for predicting posttest scores from pretest scoresSupplement 9


We will switch to z scores to show how the slope b and intercept a are determined supplement 9
We will switch to scores from pretest scoresz-scores to show how the slope (b) and intercept (a) are determinedSupplement 9


Plot z scores and regression equation supplement 9
Plot scores from pretest scoresz-scores and regression equationSupplement 9


Estimating y using z scores supplement 9
Estimating scores from pretest scoresY using z-scoresSupplement 9


Interpret predicted y scores with respect to standard deviations from the mean
Interpret predicted scores from pretest scoresY scores with respect to standard deviations from the mean?


What would we predict y to be if the correlation had been
What would we predict scores from pretest scoresY to beif the correlation had been.......

r = .50 and X was 1.0 SD above the mean?

r = .50 and X was 2.0 SDs above the mean?

r = .50 and X was 3.0 SDs above the mean?

r = .50 and X was 1.0 SD below the mean?

r = .50 and X was 3.0 SDs below the mean?

r = .50 and X was 0.5 SDs above the mean?

r = .50 and X was 0.0 SDs above the mean?


What would we predict y to be if the correlation had been1
What would we predict scores from pretest scoresY to beif the correlation had been.......

r = .10 and X was 1.0 SD above the mean?

r = .10 and X was 3.0 SDs above the mean?

r = .10 and X was 1.0 SD below the mean?

r = .10 and X was 0.0 SDs above the mean?


What would we predict y to be if the correlation had been2
What would we predict scores from pretest scoresY to beif the correlation had been.......

r = 1.00 and X was 1.0 SD above the mean?

r = 1.00 and X was 3.0 SDs above the mean?

r = 1.00 and X was 1.0 SD below the mean?

r = 1.00 and X was 0.0 SDs above the mean?


Redundant what would we predict y to be if the correlation had been
Redundant: scores from pretest scoresWhat would we predict Y to beif the correlation had been.......

  • r = .50 and X was 1.0 SD above the mean?


Redundant what would we predict y to be if the correlation had been1
Redundant: scores from pretest scoresWhat would we predict Y to beif the correlation had been.......

r = .50 and X was 1.0 SD above the mean?

What if


Redundant what would we predict y to be if the correlation had been2
Redundant: scores from pretest scoresWhat would we predict Y to beif the correlation had been.......

r = .50 and X was 1.0 SD above the mean?

What if

r = .50 and X was 3.0 SDs above the mean?

What if


What would we predict y to be if
What would we predict scores from pretest scoresY to be if ......

r = .10 and X was 1.0 SD above the mean?

r = 1.00 and X was 1.0 SD above the mean?

r = 1.00 and X was 3.0 SDs above the mean?

r = 0.50 and X was 1.0 SD below the mean?

r = 0.50 and X was 2.0 SDs above the mean?

r = 0.50 and X was at the mean?


Regression towards the mean
Regression towards the mean... scores from pretest scores

+3

+3

…if r = +1.00

+2

+2

+1

+1

0

0

-1

-1

-2

-2

-3

-3


Regression towards the mean1
Regression towards the mean... scores from pretest scores

+3

+3

…if r = +1.00

+2

+2

+1

+1

0

0

-1

-1

-2

-2

-3

-3


Regression towards the mean2
Regression towards the mean... scores from pretest scores

+3

+3

…if r = +1.00

+2

+2

+1

+1

0

0

-1

-1

-2

-2

-3

-3


Regression towards the mean3
Regression towards the mean... scores from pretest scores

+3

+3

…if r = +0.75

+2

+2

+1

+1

0

0

-1

-1

-2

-2

-3

-3


Regression towards the mean4
Regression towards the mean... scores from pretest scores

+3

+3

…if r = +0.75

+2

+2

+1

+1

0

0

-1

-1

-2

-2

-3

-3


Regression towards the mean5
Regression towards the mean... scores from pretest scores

+3

+3

…if r = +0.75

+2

+2

+1

+1

0

0

-1

-1

-2

-2

-3

-3


Regression towards the mean6
Regression towards the mean... scores from pretest scores

+3

+3

…if r = +0.50

+2

+2

+1

+1

0

0

-1

-1

-2

-2

-3

-3


Regression towards the mean7
Regression towards the mean... scores from pretest scores

+3

+3

…if r = +0.50

+2

+2

+1

+1

0

0

-1

-1

-2

-2

-3

-3


Regression towards the mean8
Regression towards the mean... scores from pretest scores

+3

+3

…if r = +0.50

+2

+2

+1

+1

0

0

-1

-1

-2

-2

-3

-3


Predicting y when given x supplement 8 page 2
Predicting Y when given X..... scores from pretest scoresSupplement 8, page 2


Predicting y when given x supplement 8 page 21
Predicting Y when given X..... scores from pretest scoresSupplement 8, page 2


Predicting y when given x supplement 8 page 22
Predicting Y when given X..... scores from pretest scoresSupplement 8, page 2


Predicting y when given x supplement 8 page 23
Predicting Y when given X..... scores from pretest scoresSupplement 8, page 2


Predicting y when given x supplement 8 page 24
Predicting Y when given X..... scores from pretest scoresSupplement 8, page 2


Predicting y when given x supplement 8 page 25
Predicting Y when given X..... scores from pretest scoresSupplement 8, page 2


Predicting y when given x supplement 8 page 26
Predicting Y when given X..... scores from pretest scoresSupplement 8, page 2


Predicting y when given x supplement 8 page 27
Predicting Y when given X..... scores from pretest scoresSupplement 8, page 2


Predicting y when given x supplement 8 page 28
Predicting Y when given X..... scores from pretest scoresSupplement 8, page 2


Predicting y when given x supplement 8 page 29
Predicting Y when given X..... scores from pretest scoresSupplement 8, page 2


Predicting y when given x
Predicting Y when given X..... scores from pretest scores


What we have been doing

4 scores from pretest scores

3

2

1

Z-score: WEIGHT

0

-1

-2

-3

-3

-2

-1

0

1

2

3

Z-score: HEIGHT

What we have been doing!


For r 75 s y 4 47 and s x 2 24 slope is adjusted from 75 to b
For scores from pretest scoresr = .75, sy = 4.47 and sx = 2.24, slope is adjusted from .75 to b = ?


For r 75 s y 4 47 and s x 2 24 slope is adjusted from 75 to b1
For scores from pretest scoresr = .75, sy = 4.47 and sx = 2.24, slope is adjusted from .75 to b = ?


If b 1 5 a take advantage of what we know about regression
If scores from pretest scoresb = 1.5, a = ?Take advantage of what we know about regression…...


If b 1 5 a take advantage of what we know about regression1
If scores from pretest scoresb = 1.5, a = ?Take advantage of what we know about regression…...

r = .75 and zx = .00, predicted zy = ?

r = .75 and zx = .00, predicted zy = .00

r = 1.00 and zx = .00, predicted zy = ?

r = 1.00 and zx = .00, predicted zy = .00

r = .00 and zx = .00, predicted zy = ?

r = .00 and zx = .00, predicted zy = .00


If scores from pretest scoresb = 1.5, a = ?Taking advantage of what we know about regression, and remembering that if zX = 0, predicted zY = .00Supplement 9, 2nd page – Example 1


Summary of 1 st example supplement 9
Summary of 1 scores from pretest scoresst ExampleSupplement 9


2 nd example supplement 9
2 scores from pretest scoresnd ExampleSupplement 9


Error in prediction residual
Error in prediction (residual) scores from pretest scores


Error in prediction i e residual supplement 9
Error in Prediction, i.e. Residual scores from pretest scoresSupplement 9


Error in prediction i e residual supplement 91
Error in Prediction, i.e. Residual scores from pretest scoresSupplement 9


Error in prediction i e residual supplement 92
Error in Prediction, i.e. Residual scores from pretest scoresSupplement 9


Standard error of estimate supplement 9
Standard Error of Estimate scores from pretest scoresSupplement 9


Standard error of estimate z scores versus raw scores
Standard error of estimate… scores from pretest scoresz-scores versus raw-scores


Z scores and raw scores the general case
z scores from pretest scores-scores and raw scores...the general case


Standard error of estimate for raw scores
Standard error of estimate scores from pretest scoresfor raw-scores


Standard error of estimate
Standard Error of Estimate scores from pretest scores

Standard deviation of Y scores for a given X score


Standard error of estimate supplement 10
Standard Error of Estimate scores from pretest scoresSupplement 10

Standard deviation of Y scores for a given X score

Using SPSS to find regression equation and standard error


Standard error of estimate supplement 101
Standard Error of Estimate scores from pretest scoresSupplement 10


3 dimensional scatter plots supplement 10
3-dimensional scatter plots…. scores from pretest scoresSupplement 10


3 dimensional scatter plots supplement 101
3-dimensional scatter plots…. scores from pretest scoresSupplement 10


3 dimensional scatter plots supplement 102
3-dimensional scatter plots…. scores from pretest scoresSupplement 10


3 dimensional scatter plots supplement 103
3-dimensional scatter plots…. scores from pretest scoresSupplement 10


Multiple regression
Multiple regression…. scores from pretest scores

Y’ = bX + a

Y’ = b1X1 + b2X2 + a

Y’ = b1X1 + b2X2 + b3X3 + a

Multiple regression with SPSS...



Correlations between
Correlations between... scores from pretest scores

  • …pretest and posttest?

  • …pretest and estimated posttest?

  • …pretest and residual?


Explained and unexplained components of variance
Explained and Unexplained Components of Variance scores from pretest scores

What variability in weight is explained versus not explained by variability in height?


Explained and unexplained variance supplement 10
Explained and Unexplained Variance scores from pretest scoresSupplement 10


Proportion of variance explained and unexplained r 2 and 1 r 2
Proportion scores from pretest scores of Variance Explained and Unexplainedr2and1-r2

Questions…

  • On graph, what variance on Y is explained by variance on X ? What variance is unexplained?

  • On the graph, where is standard error of estimate illustrated?

  • On the graph, how can be describe the criterion of least squares?

  • On the graph, what would we see if the correlation increased or decreased?


Proportion of variance explained and unexplained r 2 and 1 r 21
Proportion scores from pretest scores of Variance Explained and Unexplainedr2and1-r2

Not only height and weight…

  • Study time and test scores (r =.7)

  • GRE scores and grades (r =.4)

  • Boat registrations and manatee kills (r =.9)

  • Heights of husbands and wives (r =.6)


ad