Statistical Consultants Ltd



HomeServicesClientsPeopleBlogLinksContact

Total Least Squares



Statistical Analysis Techniques, Alternatives to OLS



OLS residualsTLS residuals

 
Total least squares is an alternative regression method to the conventional ordinary least squares (OLS).  Total Least Squares is also known as errors in variables, rigorous least squares, and orthogonal regression.  It is a generalisation of Deming regression.
 
Total least squares is similar to OLS but instead of using vertical residuals (observed response value minus fitted response value), it uses diagonal residuals (shortest distant between observation point and fitted model).
 
The reason why total least squares isn’t used as often as ordinary least squares, is because problems arise when the variables have different units of measurement.  If the variables have different units of measurement and diagonal residual are used, then essentially quantities with different measurement units are being added together (due to Pythagoras Theorem).  To overcome this problem, the variables could be normalised / standardised.
 
 
See Also:
 
Regression
LAD: An Alternative to OLS
M-Estimators
L-Estimators
R-Estimators




To comment on this or other blog posts, join the Statistical Consultants Ltd Facebook page or Google+ page.  Suggestions for blog posts are welcome.

Visit our Facebook page  Google Plus logo




HomeServicesClientsPeopleBlogLinksContact

Copyright © Statistical Consultants Ltd  2010