PSYCH 2300

Statistical technique that is used to measure and describe a relationship between two variables

The two variables tend to change in the same direction.

As the value of X increases, the Y also increases. Vice Versa

• Two variables go in opposite directions.
• As X increases, Y decreases - an inverse relationship

Identified by a correlation of 1.00 and indicates a perfectly consistent relationship

Measures the degree to and direction of the linear relationship between two variables

Measure the amount of co-variability between TWO variables

A correlation that is computed from scores that do not represent the full range of possible values, should be cautious when interpreting correlation.

• Measures the proportion of variability in one variable that can be determined from the relationship with the other variable.
• A correlation of r=0.80 (or -0.80), means that  =0.64 (or 64%) of the variability in the Y scores can be predicted from the relationship with X

• A linear relationship between two variables can be expressed by the equation:
• Where a and b are fixed constants

Slope determines how much the Y variable changes when X is increased by 1 point

• Determines the value of Y when X=0
• a value

Statistical technique for finding the best fitting straight line for a set of data

The resulting straight line

• The best fitting line has the smallest total squared error

Gives a measure of the standard distance between a regression line and the actual data points

A statistical technique used to measure the amount of variance in a data set that is not explained by the regression model

residual of an observed value is the difference between the observed value and theestimated function value