1.04 Flashcards
Correlation
A measure of the relationship between two variables.
The ice cream does not cause the shark attacks, but there is definitely a correlation between these variables.
Correlation coefficient
A number that represents the strength and directions of a relationship existing between two variables; number derived from the formula for measuring a correlation. A measure of the direction (positive or negative) and extent (range of a correlation coefficient is from -1 to +1) of the relationship between two sets of scores.
A correlation coefficient of 0 means the two variable occur at random. Like the effect of wearing shoes vs. sandals on your AP Psychology Exam.
Positive correlation
Related variables either increase or decrease in the same direction.
“The more I study, the higher my grade”
“The less I study, the lower my grade”
Negative correlation
One variable increases while the other decreases.
“The more I’m absent from school, the lower my grades”
“The more time I work, the less time I exercise”
Scatterplot
The graphic representation of correlations where data from the two variables is plotted on X and Y axes. By plotting data, the resulting graph will describe the type and strength of the correlation.
“Jazz Hands” perrrrrrrrrrr!!
Perfect Positive Correlation
Correlation value of a +1.00
The more questions you get right the higher your grade is.
Perfect Negative Correlation
Correlation value of a -1.00
The more your awake the less your sleep.
Confounding variable
An uncontrolled third variable that affects the relationship between two correlated variables.
The confounding variable in the shark vs. ice cream is the amount of people in the area.
Illusory Correlation
The tendency to believe a relationship exists when one does not.
Believing roller coasters are dangerous when there not.
