{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

lecture_2_2

# lecture_2_2 - Looking at data relationships Correlation IPS...

This preview shows pages 1–6. Sign up to view the full content.

Looking at data: relationships   Correlation IPS chapter 2.2 Copyright Brigitte Baldi 2005 ©

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Objectives (BPS chapter 2.2) Correlation The correlation coefficient “r” R does not distinguish x and y R has no units R ranges from -1 to +1 Influential points
The correlation coefficient is a measure of the direction and strength of a linear relationship between two quantitative variables x and y. The correlation coefficient "r" Student (i) IQ score (x) Self- Concept Score (y) i=1 x 1 = 110 y 1 = 58 i=2 x 2 = 124 y 2 = 72 i=3 x 3 = 126 y 3 = 80 Correlation can only be used to describe quantitative variables. Categorical variables don’t have means and standard deviations. r? of value the is What 14 . 11 s , 70 72 . 8 s , 120 y x = = = = y x

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
“r” does not distinguish x & y The correlation coefficient, r, treats x and y symmetrically. r = -0.75 r = ?
“r” does not distinguish x & y The correlation coefficient, r, treats x and y symmetrically.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}