Correlation

Correlational Research

understanding how two variables are related and relating constructs (does X cause Y, does Y cause X, does Z cause both X and Y)

Correlational Hypothesis

predicting a correlation (+ or -) (between ____ and _____) then explain the correlation

Why Correlation?

identify patterns and trends, use variable to predict score of a second variable, determine the likelihood of the pattern observed in the sample (also present in the population)

How do we evaluate if a relationship exists?

scatter plot (positive= x increases, y does too. negative= x increases, y decreases. strength= distance from 0)

Correlation Coefficient

number that tells you the strength + direction of the correlation (-1 to 1)

Causation Requires

correlation, temporal precedence, ruling out all other 3rd variables (nonspurious relationship)

Temporal Precedence

cause comes before the effect (experiments accomplish this, but surveys and correlational research don’t)

3rd Variable

when a 3rd variable correlated with one or both of the 2 variables, explains away or accounts for the correlation

Spurious Correlations

result of a third, unmeasured variable that affects both of the measures variables

Advantages

Identifies relationships and trends, practical and feasible, ethical, foundation for future research

Disadvantages

no cause and effect, third variable problem, limited scope on complex dynamics, inability to determine directionality?