A statistical association between variables
correlation
A statistical association between variables
correlation
Examining potential associations between variables. This is the research into statistical relations and the relations might be a coincidence.
correlational research
What is the difference between correlational research and causational research?
What is the same between correlational research and causational research?
Attempting to reduce confounding variables
Higher scores of one variable increase with the other variable
positive corrolation
Higher scores of one variable increase as the other variable decreases
negative corrolation
A statistical measure that measures the direction and strength of the linear relation between two variables that have been measured on an interval or ratio scale
pearson’s r
How to understand pearson’s r
the closer it is to -1.00 or 1.00, the stronger the linear relationship is
A statistic used to measure the relation between two quantitative variables when variables are measured on an ordinal scale
spearman’s rho
two things that might effect spearman’s rho
A graph in which data point portray the intersection of X and Y
scatter plot
Why use a scatter plot
Pearson’s r of .10 to .29
small association
Pearson’s r of .30 to .49
moderate association
Pearson’s r of . 50 to 1.00
strong association
What happens when pearson’s r is squared
shows the variation in the results
Three key criteria used in drawing causal inferences
Why can a correlational study not draw conclusions?
Because X variable is not manipulated, temporal order cannot be established
The problem of ambiguity about whether X did cause Y
Bidirectionality problem
The problem is that there might be another variable between X and Y
variable problem
A correlation between variable X and variable Y is computed while statistically controlling for their individual correlations with a third variable Z
Partial Correlation
Each person participates on one occasion, and all variables are measured at that time
cross-sectional research design
Data are gathered on the same individuals or groups in two or more occasions
longitudinal research design