- In any application of LOWESS, the choice of Alpha (the local smoothing width) must be based on a combination of judgment and trial and error*.
- Allowing interactive modification of the value of Alpha and viewing on the fly (i) the original LOWESS fit and (ii)
the plot of LOWESS of residuals from the original LOWESS fit, is the most interactive process for selecting the appropriate Alpha on a case-by-case basis.
* Cleveland, W. S. (1993). Visualizing Data. Hobart Press, Summit, NJ.