Examples from web-based study
Number of hitsˆ Final grade in course
Go back to web-based study and define all relationships being studied.
Correlation coefficient ( r ) indicates strength of relationship
Measuring artistic ability
Hours a day spent drawing
Understanding of spatial relationships
Get a sample of kids, measure them on all variables.
If some of the variables are related, then we zero in on what exactly artistic ability might be.
CORRELATION IS NOT CAUSATION. We aren't talking about causation right now.
READ TIME ARTICLE BEFORE THURSDAY'S CLASS
"All of statistics is about relationships, but sometimes a design doesn't quite fit correlation as a method of analysis"
If you're talking about one school that has a lot of money and a school that doesn't and you want to look a the difference, then you'll be really helped out when it comes to T-testing.
Assumptions of Pearson r
Types of correlation coefficients Ð check table.
Reading the direction of relationship:
All up to a point Ð need to know range of subjects on which we are collecting data