Unit 2 Review

attempts to explain the observed outcomes

measures the outcome of the study

shows the relationship between two quantitative variables measured on the same individuals

linear or curved

is positive, negative, or neither

is weak, moderate, or strong

lies outside the overall pattern

as one increased the other increases

as one increases the other decreases

mesures the strength and direction of the relationship between 2 quantitative variables; represented by r

• r does not change if x and/or y are changed

• positive r = positive association and negative r = negative association

• always a number between -1 and +1

• measures strength of a linear relationship

• is nonresistant

describes how a response variable y changes as explanatory variable x changes; predicts values of y for given values of x

percentage of the change in the y-variable that can be attributed to its relationship with the x-variable

difference between observed value of y and a value predicted by the regression line; residual = actual y - predicted y

scatter plot of each x-value and its residual value

the removal of the point has a large effect on the correlation and / or regression