U0, L3: Understanding Correlational Research Methods

Correlational Research

Scientific method used in psychology to examine the relationship b/w 2/more variables.

• Do not involve manipulation of variables. Studies focus on observing & measuring naturally occurring associations b/w variables

• Allows psychologists to identify patterns & make predictions, does not establish causation b/w variables

• Correlation = NOT causation

Third Variable Problem

Possibility that a 3rd, unmeasured variable may be influencing the relationship b/w 2 variables of interest

• Presence of a correlation does not imply cause & effect relationship b/w 2 factors, as there could be other factors at play

Scatterplot

Visual rep used in correlational research to display the relationship b/w 2/more variables

• Allows researchers to visually assess strength & direction of the correlation b/w variables Allows

• Helps identify outliers/unusual patterns in data

Correlation Coefficient

Statistical measure used in correlational research to quantify the strength & direction of the relationship of 2 variables

• Represented by “r”, ranges from -1 —> +1

• Closer correlation to -1/+1 = stronger the relationship b/w variables

• Stronger = predictable; Weaker = less predictable

• Correlation of 0 = no correlation

Positive Correlation

Correlation coefficient of +1 indicates a perfect positive relationship, 1 variables tends to decrease as other increases/one variable tends to increase as the other decreases

• Variables move same direction

Negative Correlation

1 variable increases, other variable decreases. Correlation coefficient of -1 indicates a perfect neg relationship.

• Variables moving in opposite directions