- Outliers: lies outside the pattern of other observations, X- outliers, Y-outliers
- Influential: Deleting this point changes your statistical analysis markedly
- Y-outliers: large residual, X-outliers: often influential in regression.
- Influential observations pull the regression line towards themselves
- Least squares regression is not robust to presence of outliers
Dr. Christina Hayes
Wilson 2-263
Department of Mathematical Sciences
Montana State University
Bozeman, MT 59717
phone: 406-994-6557
fax: 406-994-1789
christina.hayes@montana.edu
(Email will likely reach me faster than a phone call)