Download presentation

Presentation is loading. Please wait.

Published byAva Hodson Modified over 2 years ago

1
Bivariate and Partial Correlations

2
X (HT) Y (WT)............................. The Graphical View– A Scatter Diagram X’ Y’

3
The Graphical View– A Scatter Diagram X (HT) Y (WT)........................ Y BAR X BAR X’ Y’

4
The Graphical View– A Scatter Diagram X (HT) Y (WT)............................................................ X’ Y’

5
The Algebraic View – Shared Variance Take the Variance in X = S 2 x and the Variance in Y = S 2 y 1) 2) 3) 4) The correlation is simply 3) divided by 2):

6
An Example of Calculating a Correlation 1) Find the raw scores, means, squared deviations and cross-products: 3) Square r to determine variation explained r 2 =.746

7
An Example of Calculating a Correlation from SPSS INPUT

8
An Example of Calculating a Correlation from SPSS OUTPUT

9
Step 1 – Determine the zero order Pearson’s correlations (r). Assume r xy =.55 where x = divorce rate and y = suicide rates. Further, assume unemployment rate (z) is our control variable and that r xz =.60 and r yz =.40 Step 2 – Calculate the partial correlation ( r xy.z ) ==.42 Step 3 – Draw conclusions After z ( r xy.z ) 2 =.18 Before z (r xy ) 2 =.30 Therefore, Z accounts for (.30-.18) or 12% of Y and (.12/.30) or 40% of the relationship between X&Y.55 – (.6) (.4) The Partial Correlation Coefficient

10
Using SPSS for finding Partial Correlation Coefficients INPUT

11
Using SPSS for finding Partial Correlation Coefficients OUTPUT

Similar presentations

OK

Correlation. Correlation is a measure of the strength of the relation between two or more variables. Any correlation coefficient has two parts – Valence:

Correlation. Correlation is a measure of the strength of the relation between two or more variables. Any correlation coefficient has two parts – Valence:

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on interest rate parity Ppt on how to use powerpoint 2013 Ppt on solid dielectrics wiki Ppt on pi in maths what does median Ppt on holographic technology health Ppt on any business plan Ppt on channels of distribution Ppt on earthquake disaster management Ppt on soil moisture sensor Ppt on congruence of triangles class 8