Correlation Flashcards
Describe Correlation coefficients
Correlation coefficients are used to quantitatively describe the strength and direction of a relationship between two variables.
Two types of parametric statistical tests of relationship in which a correlation is provided?
1) Pearson Product Moment Correlation
2) Spearman Rank Correlation Coeffecient
Given X and Y what is the independent and dependent variables
X = Independent Variable Y = Dependent Variable
Given y = a + bx
What is a and what is b?
a is the constant (y-intercept)
b is the slope
x is the independent variable
What is the relationship if the correlation is 0 - 0.25?
No Relationship
What is the relationship if the correlation is 0.26 - 0.49?
Low Correlation (Fair)
What is the relationship if the correlation is 0.5 - 0.69?
Moderate
What is the relationship if the correlation is 0.7 - 0.89?
High
What is the relationship if the correlation is 0.9 or higher?
Very High
What is the correlation range?
-1 to +1
Describe how an inverse relationship forms
As one of the variables increases the other variable decreases
Why do we assemble scatter diagrams?
To gain insight into the relationships of two variables.
What are the 4 types of relationships?
1) Positive Relationship
2) Perfect Relationship (line of best fit goes through the origin)
3) No relationship (straight line)
4) Negative Relationship
What is the coefficient of determination?
The amount of variance in one variable that can be accounted for by the value of another variable
- Represented by r²
- Expressed as a percentage
What is a curvilinear correlation?
Any correlation in which the rates of change of the variables is not constant
For example: anxiety and test performance
